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Yao R, Liu Z, Ma Y, Xu L, He Y, Ai W, Li Y, Lu F, Dong H, Gao Z, Wang WH, Luo F. Controlled Synthesis of 2D Ferromagnetic/Antiferromagnetic Cr 7Te 8/MnTe Vertical Heterostructures for High-Tunable Coercivity. ACS NANO 2024; 18:23508-23517. [PMID: 39137306 DOI: 10.1021/acsnano.4c07128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2024]
Abstract
Two-dimensional ferromagnetic/antiferromagnetic (2D-FM/AFM) heterostructures are of great significance to realize the application of spintronic devices such as miniaturization, low power consumption, and high-density information storage. However, traditional mechanical stacking can easily damage the crystal quality or cause chemical contamination residues for 2D materials, which can result in weak interface coupling and difficulty in device regulation. Chemical vapor deposition (CVD) is an effective way to achieve a high-quality heterostructure interface. Herein, high-quality interface 2D-FM/AFM Cr7Te8/MnTe vertical heterostructures were successfully synthesized via a one-pot CVD method. Moreover, the atomic-scale structural scanning transmission electron microscope (STEM) characterization shows that the interface of the vertical heterostructure is clear and flat without an excess interface layer. Compared to the parent Cr7Te8, the coercivity (HC) of the high-quality interface Cr7Te8/MnTe heterostructure is significantly reduced as the thickness of MnTe increases, with a maximum decrease of 74.5% when the thickness of the MnTe nanosheet is around 30 nm. Additionally, the HC of the Cr7Te8/MnTe heterostructure can also be regulated by applying a gate voltage, and the HC increases or decreases with increasing positive or negative gate voltages. Thus, the effective regulation of HC is essential to improving the performance of advanced spintronic devices (e.g., MRAM and magnetic sensors). Our work will provide ideas for spin controlling and device application of 2D-FM/AFM heterostructures.
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Affiliation(s)
- Rui Yao
- Department of Electronic Science and Engineering, and Tianjin Key Laboratory of Efficient Utilization of Solar Energy, Nankai University, Tianjin 300350, China
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin 300350, China
| | - Zhaochao Liu
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin 300350, China
| | - Yifei Ma
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin 300350, China
| | - Lingyun Xu
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin 300350, China
| | - Yuyu He
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin 300350, China
| | - Wei Ai
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin 300350, China
| | - You Li
- Department of Electronic Science and Engineering, and Tianjin Key Laboratory of Efficient Utilization of Solar Energy, Nankai University, Tianjin 300350, China
| | - Feng Lu
- Department of Electronic Science and Engineering, and Tianjin Key Laboratory of Efficient Utilization of Solar Energy, Nankai University, Tianjin 300350, China
| | - Hong Dong
- Department of Electronic Science and Engineering, and Tianjin Key Laboratory of Efficient Utilization of Solar Energy, Nankai University, Tianjin 300350, China
| | - Zhansheng Gao
- Center for the Physics of Low-Dimensional Materials, Henan Joint International Research Laboratory of New Energy Materials and Devices, Henan Key Laboratory for High Efficiency Energy Conversion Science and Technology, School of Physics and Electronics, Henan University, Kaifeng 475004, China
| | - Wei-Hua Wang
- Department of Electronic Science and Engineering, and Tianjin Key Laboratory of Efficient Utilization of Solar Energy, Nankai University, Tianjin 300350, China
| | - Feng Luo
- Department of Electronic Science and Engineering, and Tianjin Key Laboratory of Efficient Utilization of Solar Energy, Nankai University, Tianjin 300350, China
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin 300350, China
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2
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Mishra S, Park IK, Javaid S, Shin SH, Lee G. Enhancement of interlayer exchange coupling via intercalation in 2D magnetic bilayers: towards high Curie temperature. MATERIALS HORIZONS 2024. [PMID: 38973585 DOI: 10.1039/d4mh00135d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
Two-dimensional magnetic materials are considered as promising candidates for developing next-generation spintronic devices by providing the possibility of scaling down to nanometers. However, a low Curie temperature is a crucial problem for practical applications, being intimately related to weak interlayer exchange coupling. Here, by using density functional theory calculations, we show that interlayer exchange coupling can be enhanced by intercalating 3d transition metals (Sc to Zn) into a bilayer of CrI3 and NiI2. It is found that intercalated Ni and Cr atoms exhibit strong antiferromagnetic coupling with the CrI3 and NiI2 host layers, respectively. This enhances the ferromagnetic interlayer exchange coupling between the host layers by many folds compared to pristine CrI3 and NiI2 bilayers. Moreover, both intercalated compounds show out-of-plane magnetic anisotropy with half metallic nature, which makes them ideal candidates for spintronics applications. Thereby our work provides a rational approach to raise the Curie temperature of non-metallic two-dimensional magnets by intercalation.
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Affiliation(s)
- Suman Mishra
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea.
| | - In Kee Park
- Department of Chemistry, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Saqib Javaid
- Department of Chemistry, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
- MMSG, Theoretical Physics Division, PINSTECH, P.O. Nilore, Islamabad, Pakistan
| | - Seung Hwan Shin
- Mutipurpose Synchrotron Radiation Construction Project, Korea Basic Science Institute, 162 Yeongudanji-ro, Cheongwon-gu, Cheongju, Chungcheongbukdo 28119, Republic of Korea.
| | - Geunsik Lee
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea.
- Department of Chemistry, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
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Stepanova AV, Mironov AV, Bogach AV, Azarevich AN, Presniakov IA, Sobolev AV, Pankratov DA, Zayakhanov VA, Starchikov SS, Verchenko VY, Shevelkov AV. Bulk ferromagnetism in cleavable van der Waals telluride NbFeTe 2. Chem Commun (Camb) 2024; 60:5518-5521. [PMID: 38693880 DOI: 10.1039/d4cc01160k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
A van der Waals telluride, NbFeTe2, has been synthesized using chemical vapor transport reactions. The optimized synthetic conditions yield high-quality single crystals with a novel monoclinic crystal structure. Monoclinic NbFeTe2 demonstrates a (100) cleavage plane, bulk ferromagnetism below 87 K, and a metallic ground state-the necessary prerequisites for needed spintronics technologies.
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Affiliation(s)
- Anna V Stepanova
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
| | - Andrei V Mironov
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
| | - Alexey V Bogach
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 119991 Moscow, Russia
| | - Andrey N Azarevich
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 119991 Moscow, Russia
| | - Igor A Presniakov
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
- MSU-BIT University, Shenzhen, 517182 Guangdong Province, P. R. China
| | - Alexey V Sobolev
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
- MSU-BIT University, Shenzhen, 517182 Guangdong Province, P. R. China
| | - Denis A Pankratov
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
| | | | | | - Valeriy Yu Verchenko
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
| | - Andrei V Shevelkov
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
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4
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Liu S, Hu S, Cui X, Kimura T. Efficient Thermo-Spin Conversion in van der Waals Ferromagnet FeGaTe. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2309776. [PMID: 38127962 DOI: 10.1002/adma.202309776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/11/2023] [Indexed: 12/23/2023]
Abstract
Recent discovery of 2D van der Waals magnetic materials has spurred progress in developing advanced spintronic devices. A central challenge lies in enhancing the spin-conversion efficiency for building spin-logic or spin-memory devices. Here, the anomalous Hall and Nernst effects are systematically investigated to uncover significant spin-conversion effects in above-room-temperature van der Waals ferromagnet FeGaTe with perpendicular magnetic anisotropy. The anomalous Hall effect demonstrates an efficient electric spin-charge conversion with a notable spin Hall angle of over 6%. In addition, the anomalous Nernst effect produces a significant transverse voltage at room temperature without a magnetic field, displaying unique temperature dependence with a maximum transverse Seebeck coefficient of 440 nV K-1 and a Nernst angle of ≈62%. Such an innovative thermoelectric signal arises from the efficient thermo-spin conversion effect, where the up-spin and down-spin electrons move in opposite directions under a temperature gradient. The present study highlights the potential of FeGaTe to enhance thermoelectric devices through efficient thermo-spin conversion without the need for a magnetic field.
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Affiliation(s)
- Shuhan Liu
- Department of Physics, Kyushu University, 744 Motooka, Fukuoka, 819-0395, Japan
| | - Shaojie Hu
- Department of Physics, Kyushu University, 744 Motooka, Fukuoka, 819-0395, Japan
| | - Xiaomin Cui
- Department of Physics, Kyushu University, 744 Motooka, Fukuoka, 819-0395, Japan
| | - Takashi Kimura
- Department of Physics, Kyushu University, 744 Motooka, Fukuoka, 819-0395, Japan
- Spintronics Research Network Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
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Wu N, Zhang S, Chen D, Wang Y, Meng S. Three-stage ultrafast demagnetization dynamics in a monolayer ferromagnet. Nat Commun 2024; 15:2804. [PMID: 38555344 PMCID: PMC10981666 DOI: 10.1038/s41467-024-47128-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 03/21/2024] [Indexed: 04/02/2024] Open
Abstract
Intense laser pulses can be used to demagnetize a magnetic material on an extremely short timescale. While this ultrafast demagnetization offers the potential for new magneto-optical devices, it poses challenges in capturing coupled spin-electron and spin-lattice dynamics. In this article, we study the photoinduced ultrafast demagnetization of a prototype monolayer ferromagnet Fe3GeTe2 and resolve the three-stage demagnetization process characterized by an ultrafast and substantial demagnetization on a timescale of 100 fs, followed by light-induced coherent A1g phonon dynamics which is strongly coupled to the spin dynamics in the next 200-800 fs. In the third stage, chiral lattice vibrations driven by nonlinear phonon couplings, both in-plane and out-of-plane are produced, resulting in significant spin precession. Nonadiabatic effects are found to introduce considerable phonon hardening and suppress the spin-lattice couplings during demagnetization. Our results advance our understanding of dynamic charge-spin-lattice couplings in the ultrafast demagnetization and evidence angular momentum transfer between the phonon and spin degrees of freedom.
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Affiliation(s)
- Na Wu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Shengjie Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Daqiang Chen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Yaxian Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Sheng Meng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China.
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China.
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6
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Kajale SN, Nguyen T, Hung NT, Li M, Sarkar D. Field-free deterministic switching of all-van der Waals spin-orbit torque system above room temperature. SCIENCE ADVANCES 2024; 10:eadk8669. [PMID: 38489365 PMCID: PMC10942109 DOI: 10.1126/sciadv.adk8669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 02/08/2024] [Indexed: 03/17/2024]
Abstract
Two-dimensional van der Waals (vdW) magnetic materials hold promise for the development of high-density, energy-efficient spintronic devices for memory and computation. Recent breakthroughs in material discoveries and spin-orbit torque control of vdW ferromagnets have opened a path for integration of vdW magnets in commercial spintronic devices. However, a solution for field-free electric control of perpendicular magnetic anisotropy (PMA) vdW magnets at room temperatures, essential for building compact and thermally stable spintronic devices, is still missing. Here, we report a solution for the field-free, deterministic, and nonvolatile switching of a PMA vdW ferromagnet, Fe3GaTe2, above room temperature (up to 320 K). We use the unconventional out-of-plane anti-damping torque from an adjacent WTe2 layer to enable such switching with a low current density of 2.23 × 106 A cm-2. This study exemplifies the efficacy of low-symmetry vdW materials for spin-orbit torque control of vdW ferromagnets and provides an all-vdW solution for the next generation of scalable and energy-efficient spintronic devices.
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Affiliation(s)
- Shivam N. Kajale
- MIT Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Thanh Nguyen
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Nguyen Tuan Hung
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Mingda Li
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Deblina Sarkar
- MIT Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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7
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Li P, Tao L, Jin X, Wan G, Zhang J, Zhang YF, Sun JT, Pan J, Du S. Nonvolatile Multistate Manipulation of Topological Magnetism in Monolayer CrI 3 through Quadruple-Well Ferroelectric Materials. NANO LETTERS 2024; 24:2345-2351. [PMID: 38334460 DOI: 10.1021/acs.nanolett.3c04799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Nonvolatile multistate manipulation of two-dimensional (2D) magnetic materials holds promise for low dissipation, highly integrated, and versatile spintronic devices. Here, utilizing density functional theory calculations and Monte Carlo simulations, we report the realization of nonvolatile and multistate control of topological magnetism in monolayer CrI3 by constructing multiferroic heterojunctions with quadruple-well ferroelectric (FE) materials. The Pt2Sn2Te6/CrI3 heterojunction exhibits multiple magnetic phases upon modulating FE polarization states of FE layers and interlayer sliding. These magnetic phases include Bloch-type skyrmions and ferromagnetism, as well as a newly discovered topological magnetic structure. We reveal that the Dzyaloshinskii-Moriya interaction (DMI) induced by interfacial coupling plays a crucial role in magnetic skyrmion manipulation, which aligns with the Fert-Levy mechanism. Moreover, a regular magnetic skyrmion lattice survives when removing a magnetic field, demonstrating its robustness. The work sheds light on an effective approach to nonvolatile and multistate control of 2D magnetic materials.
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Affiliation(s)
- Peixuan Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Tao
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xin Jin
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guolin Wan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Zhang
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan-Fang Zhang
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jia-Tao Sun
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Jinbo Pan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Shixuan Du
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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8
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Guillet T, Galceran R, Sierra JF, Belarre FJ, Ballesteros B, Costache MV, Dosenovic D, Okuno H, Marty A, Jamet M, Bonell F, Valenzuela SO. Spin-Orbit Torques and Magnetization Switching in (Bi,Sb) 2Te 3/Fe 3GeTe 2 Heterostructures Grown by Molecular Beam Epitaxy. NANO LETTERS 2024; 24:822-828. [PMID: 38263950 DOI: 10.1021/acs.nanolett.3c03291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
Topological insulators (TIs) hold promise for manipulating the magnetization of a ferromagnet (FM) through the spin-orbit torque (SOT) mechanism. However, integrating TIs with conventional FMs often leads to significant device-to-device variations and a broad distribution of SOT magnitudes. In this work, we present a scalable approach to grow a full van der Waals FM/TI heterostructure by molecular beam epitaxy, combining the charge-compensated TI (Bi,Sb)2Te3 with 2D FM Fe3GeTe2 (FGT). Harmonic magnetotransport measurements reveal that the SOT efficiency exhibits a non-monotonic temperature dependence and experiences a substantial enhancement with a reduction of the FGT thickness to 2 monolayers. Our study further demonstrates that the magnetization of ultrathin FGT films can be switched with a current density of Jc ∼ 1010 A/m2, with minimal device-to-device variations compared to previous investigations involving traditional FMs.
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Affiliation(s)
- Thomas Guillet
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Regina Galceran
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Juan F Sierra
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Francisco J Belarre
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Belén Ballesteros
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Marius V Costache
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | | | - Hanako Okuno
- Univ. Grenoble Alpes, CEA, IRIG-MEM, 38000 Grenoble, France
| | - Alain Marty
- Univ. Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-SPINTEC, 38000 Grenoble, France
| | - Matthieu Jamet
- Univ. Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-SPINTEC, 38000 Grenoble, France
| | - Frédéric Bonell
- Univ. Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-SPINTEC, 38000 Grenoble, France
| | - Sergio O Valenzuela
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08070 Barcelona, Spain
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Lohmann M, Wickramaratne D, Moon J, Noyan M, Chuang HJ, Jonker BT, Li CH. Highly Efficient Spin-Orbit Torque Switching in Bi 2Se 3/Fe 3GeTe 2 van der Waals Heterostructures. ACS NANO 2024; 18:680-690. [PMID: 38109771 DOI: 10.1021/acsnano.3c09041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
Topological insulators (TIs) have shown promise as a spin-generating layer to switch the magnetization state of ferromagnets via spin-orbit torque (SOT) due to charge-to-spin conversion efficiency of the TI surface states that arises from spin-momentum locking. However, when TIs are interfaced with conventional bulk ferromagnetic metals, the combination of charge transfer and hybridization can potentially destroy the spin texture and hamper the possibility of accessing the TI surface states. Here, we fabricate an all van der Waals (vdW) heterostructure consisting of molecular beam epitaxy grown bulk-insulating Bi2Se3 and exfoliated 2D metallic ferromagnet Fe3GeTe2 (FGT) with perpendicular anisotropy. By detecting the magnetization state of the FGT via anomalous Hall effect and magneto-optical Kerr effect measurements, we determine the critical switching current density for magnetization switching to be Jc ≈ 1.2 × 106 A/cm2, the lowest reported for the switching of a perpendicular anisotropy ferromagnet using Bi2Se3. From second harmonic Hall measurements, we further determine the SOT efficiency (ξDL) to be in the range of 1.8 ± 0.3 and 1.4 ± 0.08 between 5 and 150 K, comparable to the highest values reported for Bi2Se3. Our density functional theory calculations find that the weak interlayer interactions at the Bi2Se3/FGT interface lead to a weakened dipole at the interface and suppress the proximity induced magnetic moment on Bi2Se3. This enables direct access to the TI surface states contributed by the first quintuple layer, where the spins are singly degenerate with significant net in-plane spin polarization. Our results highlight the clear advantage of all-vdW heterostructures with weak interlayer interactions that can enhance SOT efficiency and minimize critical current density, an important step toward realizing next generation low-power nonvolatile memory and spintronic devices.
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Affiliation(s)
- Mark Lohmann
- Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
- American Society for Engineering Education, Washington, D.C. 20036, United States
| | - Darshana Wickramaratne
- Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Jisoo Moon
- Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
- National Research Council, Washington, D.C. 20001, United States
| | - Mehmet Noyan
- Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Hsun-Jen Chuang
- Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Berend T Jonker
- Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Connie H Li
- Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
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10
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Obaidulla SM, Supina A, Kamal S, Khan Y, Kralj M. van der Waals 2D transition metal dichalcogenide/organic hybridized heterostructures: recent breakthroughs and emerging prospects of the device. NANOSCALE HORIZONS 2023; 9:44-92. [PMID: 37902087 DOI: 10.1039/d3nh00310h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
The near-atomic thickness and organic molecular systems, including organic semiconductors and polymer-enabled hybrid heterostructures, of two-dimensional transition metal dichalcogenides (2D-TMDs) can modulate their optoelectronic and transport properties outstandingly. In this review, the current understanding and mechanism of the most recent and significant breakthrough of novel interlayer exciton emission and its modulation by harnessing the band energy alignment between TMDs and organic semiconductors in a TMD/organic (TMDO) hybrid heterostructure are demonstrated. The review encompasses up-to-date device demonstrations, including field-effect transistors, detectors, phototransistors, and photo-switchable superlattices. An exploration of distinct traits in 2D-TMDs and organic semiconductors delves into the applications of TMDO hybrid heterostructures. This review provides insights into the synthesis of 2D-TMDs and organic layers, covering fabrication techniques and challenges. Band bending and charge transfer via band energy alignment are explored from both structural and molecular orbital perspectives. The progress in emission modulation, including charge transfer, energy transfer, doping, defect healing, and phase engineering, is presented. The recent advancements in 2D-TMDO-based optoelectronic synaptic devices, including various 2D-TMDs and organic materials for neuromorphic applications are discussed. The section assesses their compatibility for synaptic devices, revisits the operating principles, and highlights the recent device demonstrations. Existing challenges and potential solutions are discussed. Finally, the review concludes by outlining the current challenges that span from synthesis intricacies to device applications, and by offering an outlook on the evolving field of emerging TMDO heterostructures.
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Affiliation(s)
- Sk Md Obaidulla
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička Cesta 46, HR-10000 Zagreb, Croatia.
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Sector III, Block JD, Salt Lake, Kolkata 700106, India
| | - Antonio Supina
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička Cesta 46, HR-10000 Zagreb, Croatia.
- Chair of Physics, Montanuniversität Leoben, Franz Josef Strasse 18, 8700 Leoben, Austria
| | - Sherif Kamal
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička Cesta 46, HR-10000 Zagreb, Croatia.
| | - Yahya Khan
- Department of Physics, Karakoram International university (KIU), Gilgit 15100, Pakistan
| | - Marko Kralj
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička Cesta 46, HR-10000 Zagreb, Croatia.
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11
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Yang J, Wang X, Li S, Wang X, Pan M, Ai M, Yuan H, Peng X, Wang R, Li Q, Zheng F, Zhang P. Robust Two-Dimensional Ferromagnetism in Cr 5Te 8/CrTe 2 Heterostructure with Curie Temperature above 400 K. ACS NANO 2023; 17:23160-23168. [PMID: 37926969 DOI: 10.1021/acsnano.3c09654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2023]
Abstract
The discovery of ferromagnetism in two-dimensional (2D) van der Waals crystals has generated widespread interest. The seeking of robust 2D ferromagnets with high Curie temperature (Tc) is vitally important for next-generation spintronic devices. However, owing to the enhanced spin fluctuation and weak exchange interaction upon the reduced dimensionalities, the exploring of robust 2D ferromagnets with Tc > 300 K is highly demanded but remains challenging. In this work, we fabricated air-stable 2D Cr5Te8/CrTe2 vertical heterojunctions with Tc above 400 K by the chemical vapor deposition method. Transmission electron microscopy demonstrates a high-quality-crystalline epitaxial structure between tri-Cr5Te8 and 1T-CrTe2 with striped moiré patterns and a superior ambient stability over six months. A built-in dual-axis strain together with strong interfacial coupling cooperatively leads to a record-high Tc for the CrxTey family. A temperature-dependent spin-flip process induces the easy axis of magnetization to rotate from the out-of-plane to the in-plane direction, indicating a phase-dependent proximity coupling effect, rationally interpreted by first-principles calculations of the magnetic anisotropy of a tri-Cr5Te8 and 1T-CrTe2 monolayer. Our results provide a material realization of effectively enhancing the transition temperature of 2D ferromagnetism and manipulating the spin-flip of the easy axis, which will facilitate future spintronic applications.
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Affiliation(s)
- Jielin Yang
- School of Physics, Hubei University, Wuhan 430062, China
| | - Xinyu Wang
- School of Physics, Hubei University, Wuhan 430062, China
| | - Shujing Li
- College of Mathematics and Physics, Beijing University of Chemical Technology, Beijing 100029, China
| | - Xina Wang
- School of Physics, Hubei University, Wuhan 430062, China
| | - Minghu Pan
- School of Physics & Information Technology, Shaanxi Normal University, Xi'an 710119, China
| | - Mingzhong Ai
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Hui Yuan
- School of Physics, Hubei University, Wuhan 430062, China
| | - Xiaoniu Peng
- School of Physics, Hubei University, Wuhan 430062, China
| | - Ruilong Wang
- School of Physics, Hubei University, Wuhan 430062, China
| | - Quan Li
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Fawei Zheng
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
| | - Ping Zhang
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
- School of Physics and Physical Engineering, Qufu Normal University, Qufu 273165, China
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12
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Ren H, Lan M. Progress and Prospects in Metallic Fe xGeTe 2 (3 ≤ x ≤ 7) Ferromagnets. Molecules 2023; 28:7244. [PMID: 37959664 PMCID: PMC10649090 DOI: 10.3390/molecules28217244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/05/2023] [Accepted: 10/21/2023] [Indexed: 11/15/2023] Open
Abstract
Thermal fluctuations in two-dimensional (2D) isotropy systems at non-zero finite temperatures can destroy the long-range (LR) magnetic order due to the mechanisms addressed in the Mermin-Wanger theory. However, the magnetic anisotropy related to spin-orbit coupling (SOC) may stabilize magnetic order in 2D systems. Very recently, 2D FexGeTe2 (3 ≤ x ≤ 7) with a high Curie temperature (TC) has not only undergone significant developments in terms of synthetic methods and the control of ferromagnetism (FM), but is also being actively explored for applications in various devices. In this review, we introduce six experimental methods, ten ferromagnetic modulation strategies, and four spintronic devices for 2D FexGeTe2 materials. In summary, we outline the challenges and potential research directions in this field.
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Affiliation(s)
- Hongtao Ren
- School of Materials Science and Engineering, Liaocheng University, Liaocheng 252000, China
| | - Mu Lan
- College of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China
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13
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Zhao Q, Zhu Y, Zhang H, Jiang B, Wang Y, Xie T, Lou K, Xia C, Yang H, Bi C. Proximity-Induced Interfacial Room-Temperature Ferromagnetism in Semiconducting Fe 3GeTe 2. ACS APPLIED MATERIALS & INTERFACES 2023; 15:46520-46526. [PMID: 37738105 DOI: 10.1021/acsami.3c09932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
The discoveries of two-dimensional ferromagnetism and magnetic semiconductors highly enrich the magnetic material family for constructing spin-based electronic devices, but with an acknowledged challenge that the Curie temperature (Tc) is usually far below room temperature. Many efforts such as voltage control and magnetic ion doping are currently underway to enhance the functional temperature, in which the involvement of additional electrodes or extra magnetic ions limits their application in practical devices. Here we demonstrate that the magnetic proximity, a robust effect but with elusive mechanisms, can induce room-temperature ferromagnetism at the interface between sputtered Pt and semiconducting Fe3GeTe2, both of which do not show ferromagnetism at 300 K. The independent electrical and magnetization measurements, structure analysis, and control samples with Ta highlighting the role of Pt confirm that the ferromagnetism with the Tc of above 400 K arises from the Fe3GeTe2/Pt interfaces, rather than Fe aggregation or other artificial effects. Moreover, contrary to conventional ferromagnet/Pt structures, the spin current generated by the Pt layer is enhanced more than two times at the Fe3GeTe2/Pt interfaces, indicating the potential applications of the unique proximity effect in building highly efficient spintronic devices. These results may pave a new avenue to create room-temperature functional spin devices based on low-Tc materials and provide clear evidence of magnetic proximity effects by using nonferromagnetic materials.
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Affiliation(s)
- Qianwen Zhao
- Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yingmei Zhu
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Hanying Zhang
- Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Baiqing Jiang
- Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuan Wang
- Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tunan Xie
- Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kaihua Lou
- Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - ChaoChao Xia
- Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- School of Microelectronics, University of Science and Technology of China, Hefei 230026, China
| | - Hongxin Yang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Chong Bi
- Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- School of Microelectronics, University of Science and Technology of China, Hefei 230026, China
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14
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Zhang J, He Z, Gao C, Tao Y, Liang F, Li G, Gao B, Song G. Intrinsic half-metallicity in two-dimensional Cr 2TeX 2 (X = I, Br, Cl) monolayers. RSC Adv 2023; 13:29721-29728. [PMID: 37822665 PMCID: PMC10562977 DOI: 10.1039/d3ra05780a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 09/27/2023] [Indexed: 10/13/2023] Open
Abstract
Two-dimensional (2D) materials with intrinsic half-metallicity at or above room temperature are important in spin nanodevices. Nevertheless, such 2D materials in experiment are still rarely realized. In this work, a new family of 2D Cr2TeX2 (X = I, Br, Cl) monolayers has been predicted using first-principles calculations. The monolayer is made of five atomic sublayers with ABCAB-type stacking along the perpendicular direction. It is found that the energies for all the ferromagnetic (FM) half-metallic states are the lowest. The phonon spectrum calculations and molecular dynamics simulations both demonstrate that the FM states are stable, indicating the possibility of experimentally obtaining the 2D Cr2TeX2 monolayers with half-metallicity. The Curie temperatures from Monte Carlo simulations are 486, 445, and 451 K for Cr2TeI2, Cr2TeBr2, and Cr2TeCl2 monolayers, respectively, and their half-metallic bandgaps are 1.72, 1.86 and 1.90 eV. The corresponding magnetocrystalline anisotropy energies (MAEs) are about 1185, 502, 899 μeV per Cr atom for Cr2TeX2 monolayers, in which the easy axes are along the plane for the Cr2TeBr2 and Cr2TeCl2 monolayers, but being out of the plane in the Cr2TeI2. Our study implies the potential application of the 2D Cr2TeX2 (X = I, Br, Cl) monolayers in spin nanodevices.
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Affiliation(s)
- Jun Zhang
- Department of Physics, Huaiyin Institute of Technology 1 Meicheng East Road Huaian 223003 China
| | - Zixin He
- Department of Physics, Huaiyin Institute of Technology 1 Meicheng East Road Huaian 223003 China
| | - Chuchu Gao
- Department of Physics, Huaiyin Institute of Technology 1 Meicheng East Road Huaian 223003 China
| | - Yanyan Tao
- Department of Physics, Huaiyin Institute of Technology 1 Meicheng East Road Huaian 223003 China
| | - Feng Liang
- Department of Physics, Huaiyin Institute of Technology 1 Meicheng East Road Huaian 223003 China
| | - Guannan Li
- Department of Physics, Huaiyin Institute of Technology 1 Meicheng East Road Huaian 223003 China
| | - Benling Gao
- Department of Physics, Huaiyin Institute of Technology 1 Meicheng East Road Huaian 223003 China
| | - Guang Song
- Department of Physics, Huaiyin Institute of Technology 1 Meicheng East Road Huaian 223003 China
- Department of Physics, Nanjing University 22 Hankou Road Nanjing 210093 China
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15
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Man P, Huang L, Zhao J, Ly TH. Ferroic Phases in Two-Dimensional Materials. Chem Rev 2023; 123:10990-11046. [PMID: 37672768 DOI: 10.1021/acs.chemrev.3c00170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Two-dimensional (2D) ferroics, namely ferroelectric, ferromagnetic, and ferroelastic materials, are attracting rising interest due to their fascinating physical properties and promising functional applications. A variety of 2D ferroic phases, as well as 2D multiferroics and the novel 2D ferrovalleytronics/ferrotoroidics, have been recently predicted by theory, even down to the single atomic layers. Meanwhile, some of them have already been experimentally verified. In addition to the intrinsic 2D ferroics, appropriate stacking, doping, and defects can also artificially regulate the ferroic phases of 2D materials. Correspondingly, ferroic ordering in 2D materials exhibits enormous potential for future high density memory devices, energy conversion devices, and sensing devices, among other applications. In this paper, the recent research progresses on 2D ferroic phases are comprehensively reviewed, with emphasis on chemistry and structural origin of the ferroic properties. In addition, the promising applications of the 2D ferroics for information storage, optoelectronics, and sensing are also briefly discussed. Finally, we envisioned a few possible pathways for the future 2D ferroics research and development. This comprehensive overview on the 2D ferroic phases can provide an atlas for this field and facilitate further exploration of the intriguing new materials and physical phenomena, which will generate tremendous impact on future functional materials and devices.
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Affiliation(s)
- Ping Man
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, P. R. China
| | - Lingli Huang
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, P. R. China
| | - Jiong Zhao
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong 999077, P. R. China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057, P. R. China
| | - Thuc Hue Ly
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, P. R. China
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
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16
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Liu P, Zhang Y, Li K, Li Y, Pu Y. Recent advances in 2D van der Waals magnets: Detection, modulation, and applications. iScience 2023; 26:107584. [PMID: 37664598 PMCID: PMC10470320 DOI: 10.1016/j.isci.2023.107584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023] Open
Abstract
The emergence of two-dimensional (2D) van der Waals magnets provides an exciting platform for exploring magnetism in the monolayer limit. Exotic quantum phenomena and significant potential for spintronic applications are demonstrated in 2D magnetic crystals and heterostructures, which offer unprecedented possibilities in advanced formation technology with low power and high efficiency. In this review, we summarize recent advances in 2D van der Waals magnetic crystals. We focus mainly on van der Waals materials of truly 2D nature with intrinsic magnetism. The detection methods of 2D magnetic materials are first introduced in detail. Subsequently, the effective strategies to modulate the magnetic behavior of 2D magnets (e.g., Curie temperature, magnetic anisotropy, magnetic exchange interaction) are presented. Then, we list the applications of 2D magnets in the spintronic devices. We also highlight current challenges and broad space for the development of 2D magnets in further studies.
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Affiliation(s)
- Ping Liu
- School of Science & New Energy Technology Engineering Laboratory of Jiangsu Province, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Ying Zhang
- Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei 230026, China
| | - Kehan Li
- School of Science & New Energy Technology Engineering Laboratory of Jiangsu Province, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Yongde Li
- School of Science & New Energy Technology Engineering Laboratory of Jiangsu Province, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Yong Pu
- School of Science & New Energy Technology Engineering Laboratory of Jiangsu Province, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
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17
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Yagan R, Cheghabouri AM, Onbasli MC. Stabilization and adiabatic control of antiferromagnetically coupled skyrmions without the topological Hall effect. NANOSCALE ADVANCES 2023; 5:4470-4479. [PMID: 37638152 PMCID: PMC10448311 DOI: 10.1039/d3na00236e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/26/2023] [Indexed: 08/29/2023]
Abstract
Synthetic antiferromagnetically coupled (SAF) multilayers provide different physics of stabilizing skyrmions while eliminating the topological Hall effect (THE), enabling efficient and stable control. The effects of material parameters, external current drive, and a magnetic field on the skyrmion equilibrium and propagation characteristics are largely unresolved. Here, we present a computational and theoretical demonstration of the large window of material parameters that stabilize SAF skyrmions determined by saturation magnetization, uniaxial anisotropy, and Dzyaloshinskii-Moriya interaction. Current-driven SAF skyrmion velocities reach ∼200 m s-1 without the THE. The SAF velocities are about 3-10 times greater than the typical ferromagnetic skyrmion velocities. The current densities needed for driving SAF skyrmions could be reduced to 108 A m-2, while 1011 A m-2 or above is needed for ferromagnetic skyrmions. By reducing the SAF skyrmion drive current by 3 orders, Joule heating is reduced by 6 orders of magnitude. These results pave the way for new SAF interfaces with improved equilibrium, dynamics, and power savings in THE-free skyrmionics.
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Affiliation(s)
- Rawana Yagan
- Department of Electrical and Electronics Engineering, Koç University Sarıyer Istanbul 34450 Turkey
| | | | - Mehmet C Onbasli
- Department of Electrical and Electronics Engineering, Koç University Sarıyer Istanbul 34450 Turkey
- Department of Physics, Koç University Sarıyer Istanbul 34450 Turkey
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18
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Wang H, Wu H, Zhang J, Liu Y, Chen D, Pandey C, Yin J, Wei D, Lei N, Shi S, Lu H, Li P, Fert A, Wang KL, Nie T, Zhao W. Room temperature energy-efficient spin-orbit torque switching in two-dimensional van der Waals Fe 3GeTe 2 induced by topological insulators. Nat Commun 2023; 14:5173. [PMID: 37620355 PMCID: PMC10449904 DOI: 10.1038/s41467-023-40714-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 08/07/2023] [Indexed: 08/26/2023] Open
Abstract
Two-dimensional (2D) ferromagnetic materials with unique magnetic properties have great potential for next-generation spintronic devices with high flexibility, easy controllability, and high heretointegrability. However, realizing magnetic switching with low power consumption at room temperature is challenging. Here, we demonstrate the room-temperature spin-orbit torque (SOT) driven magnetization switching in an all-van der Waals (vdW) heterostructure using an optimized epitaxial growth approach. The topological insulator Bi2Te3 not only raises the Curie temperature of Fe3GeTe2 (FGT) through interfacial exchange coupling but also works as a spin current source allowing the FGT to switch at a low current density of ~2.2×106 A/cm2. The SOT efficiency is ~2.69, measured at room temperature. The temperature and thickness-dependent SOT efficiency prove that the larger SOT in our system mainly originates from the nontrivial topological origin of the heterostructure. Our experiments enable an all-vdW SOT structure and provides a solid foundation for the implementation of room-temperature all-vdW spintronic devices in the future.
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Affiliation(s)
- Haiyu Wang
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China
- Shenyuan Honors College, Beihang University, Beijing, China
| | - Hao Wu
- Department of Electrical and Computer Engineering, and Department of Physics and Astronomy, University of California, Los Angeles, CA, USA
| | - Jie Zhang
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China
| | - Yingjie Liu
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China
| | - Dongdong Chen
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing, China
| | - Chandan Pandey
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China
| | - Jialiang Yin
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China
| | - Dahai Wei
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing, China
| | - Na Lei
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China
| | - Shuyuan Shi
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China
| | - Haichang Lu
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China
| | - Peng Li
- Department of Electrical and Computer Engineering, Auburn University, Auburn, Alabama, USA
| | - Albert Fert
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China
- Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, University of Paris-Saclay, Palaiseau, France
| | - Kang L Wang
- Department of Electrical and Computer Engineering, and Department of Physics and Astronomy, University of California, Los Angeles, CA, USA
| | - Tianxiao Nie
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China.
| | - Weisheng Zhao
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China.
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19
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Ren H, Xiang G. Strain Engineering of Intrinsic Ferromagnetism in 2D van der Waals Materials. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2378. [PMID: 37630963 PMCID: PMC10459406 DOI: 10.3390/nano13162378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 08/09/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023]
Abstract
Since the discovery of the low-temperature, long-range ferromagnetic order in monolayers Cr2Ge2Te6 and CrI3, many efforts have been made to achieve a room temperature (RT) ferromagnet. The outstanding deformation ability of two-dimensional (2D) materials provides an exciting way to mediate their intrinsic ferromagnetism (FM) with strain engineering. Here, we summarize the recent progress of strain engineering of intrinsic FM in 2D van der Waals materials. First, we introduce how to explain the strain-mediated intrinsic FM on Cr-based and Fe-based 2D van der Waals materials through ab initio Density functional theory (DFT), and how to calculate magnetic anisotropy energy (MAE) and Curie temperature (TC) from the interlayer exchange coupling J. Subsequently, we focus on numerous attempts to apply strain to 2D materials in experiments, including wrinkle-induced strain, flexible substrate bending or stretching, lattice mismatch, electrostatic force and field-cooling. Last, we emphasize that this field is still in early stages, and there are many challenges that need to be overcome. More importantly, strengthening the guideline of strain-mediated FM in 2D van der Waals materials will promote the development of spintronics and straintronics.
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Affiliation(s)
- Hongtao Ren
- School of Materials Science and Engineering, Liaocheng University, Hunan Road No. 1, Liaocheng 252000, China
| | - Gang Xiang
- College of Physics, Sichuan University, Wangjiang Road No. 29, Chengdu 610064, China
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20
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Wang G, Hu T, Xiong Y, Liu X, Shen S, Wang J, Che M, Cui Z, Zhang Y, Yang L, Li Z, Lu Y, Tian M. Electric-field control of reversible electronic and magnetic transitions in two-dimensional oxide monolayer magnets. Sci Bull (Beijing) 2023; 68:1632-1639. [PMID: 37429776 DOI: 10.1016/j.scib.2023.06.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 05/27/2023] [Accepted: 06/25/2023] [Indexed: 07/12/2023]
Abstract
Atomically thin oxide magnetic materials are highly desirable due to the promising potential to integrate two-dimensional (2D) magnets into next-generation spintronics. Therefore, 2D oxide magnetism is expected to be effectively tuned by the magnetic and electrical fields, holding prospective for future low-dissipation electronic devices. However, the electric-field control of 2D oxide monolayer magnetism has rarely been reported. Here, we present the realization of 2D monolayer magnetism in oxide (SrRuO3)1/(SrTiO3)N (N = 1, 3) superlattices that shows an efficient and reversible phase transition through electric-field controlled proton (H+) evolution. By using ionic liquid gating to modulate the proton concentration in (SrRuO3)1/(SrTiO3)1 superlattice, an electric-field induced metal-insulator transition was observed, along with gradually suppressed magnetic ordering and modulated magnetic anisotropy. Theoretical analysis reveals that proton intercalation plays a crucial role in both electronic and magnetic phase transitions. Strikingly, SrTiO3 layers can act as a proton sieve, which have a significant influence on proton evolution. Our work stimulates the tuning functionality of 2D oxide monolayer magnetism by voltage control, providing potential for future energy-efficient electronics.
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Affiliation(s)
- Guopeng Wang
- School of Physics and Optoelectronics Engineering, Anhui University, Hefei 230601, China.
| | - Tao Hu
- School of Physics and Optoelectronics Engineering, Anhui University, Hefei 230601, China
| | - Yimin Xiong
- School of Physics and Optoelectronics Engineering, Anhui University, Hefei 230601, China; Hefei National Laboratory, Hefei 230028, China
| | - Xue Liu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Shengchun Shen
- Department of Physics, University of Science and Technology of China, Hefei 230026, China
| | - Jianlin Wang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Mengqian Che
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Zhangzhang Cui
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei 230026, China.
| | - Yingying Zhang
- State Key Laboratory for New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
| | - Luyi Yang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Zhengcao Li
- State Key Laboratory for New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Yalin Lu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Mingliang Tian
- School of Physics and Optoelectronics Engineering, Anhui University, Hefei 230601, China.
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21
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Wang H, Wen Y, Zeng H, Xiong Z, Tu Y, Zhu H, Cheng R, Yin L, Jiang J, Zhai B, Liu C, Shan C, He J. 2D Ferroic Materials for Nonvolatile Memory Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2305044. [PMID: 37486859 DOI: 10.1002/adma.202305044] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 07/21/2023] [Indexed: 07/26/2023]
Abstract
The emerging nonvolatile memory technologies based on ferroic materials are promising for producing high-speed, low-power, and high-density memory in the field of integrated circuits. Long-range ferroic orders observed in 2D materials have triggered extensive research interest in 2D magnets, 2D ferroelectrics, 2D multiferroics, and their device applications. Devices based on 2D ferroic materials and heterostructures with an atomically smooth interface and ultrathin thickness have exhibited impressive properties and significant potential for developing advanced nonvolatile memory. In this context, a systematic review of emergent 2D ferroic materials is conducted here, emphasizing their recent research on nonvolatile memory applications, with a view to proposing brighter prospects for 2D magnetic materials, 2D ferroelectric materials, 2D multiferroic materials, and their relevant devices.
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Affiliation(s)
- Hao Wang
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Yao Wen
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Hui Zeng
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Ziren Xiong
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Yangyuan Tu
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Hao Zhu
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Ruiqing Cheng
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Lei Yin
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Jian Jiang
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Baoxing Zhai
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Chuansheng Liu
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Chongxin Shan
- Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, Key Laboratory of Material Physics, Ministry of Education, School of Physics, Zhengzhou University, Zhengzhou, 450052, China
| | - Jun He
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
- Hubei Luojia Laboratory, Wuhan, 430079, China
- Wuhan Institute of Quantum Technology, Wuhan, 430206, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100190, China
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22
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Cheng R, Kum HS, He J. Adding spinels to the magnetic 2D toolkit. Sci Bull (Beijing) 2023:S2095-9273(23)00310-9. [PMID: 37211488 DOI: 10.1016/j.scib.2023.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- Ruiqing Cheng
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China; Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004, China.
| | - Hyun S Kum
- Department of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, South Korea.
| | - Jun He
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China; Wuhan Institute of Quantum Technology, Wuhan 430206, China.
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23
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Wang H, Wen Y, Zhao X, Cheng R, Yin L, Zhai B, Jiang J, Li Z, Liu C, Wu F, He J. Heteroepitaxy of 2D CuCr 2 Te 4 with Robust Room-temperature Ferromagnetism. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2211388. [PMID: 36780341 DOI: 10.1002/adma.202211388] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/21/2023] [Indexed: 05/05/2023]
Abstract
Magnetic materials in 2D have attracted widespread attention for their intriguing magnetic properties. 2D magnetic heterostructures can provide unprecedented opportunities for exploring fundamental physics and novel spintronic devices. Here, the heteroepitaxial growth of ferromagnetic CuCr2 Te4 nanosheets is reported on Cr2 Te3 and mica by chemical vapor deposition. Magneto-optical Kerr effect measurements reveal the thickness-dependent ferromagnetism of CuCr2 Te4 nanosheets on mica, where a decrease of Curie temperature (TC ) from 320 to 260 K and an enhancement of perpendicular magnetic anisotropy with reducing thickness are observed. Moreover, lattice-matched heteroepitaxial ultrathin CuCr2 Te4 on Cr2 Te3 exhibits an enhanced robust ferromagnetism with TC up to 340 K due to the interfacial charge transfer. Stripe-type magnetic domains and single magnetic domain are discovered in this heterostructure with different thicknesses. The work provides a way to construct robust room-temperature 2D magnetic heterostructures for functional spintronic devices.
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Affiliation(s)
- Hao Wang
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Yao Wen
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Xiaoxu Zhao
- School of Materials Science and Engineering, Peking University, Beijing, 100871, P. R. China
| | - Ruiqing Cheng
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Lei Yin
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Baoxing Zhai
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Jian Jiang
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Zhongwei Li
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Chuansheng Liu
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Fengcheng Wu
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
- Wuhan Institute of Quantum Technology, Wuhan, 430206, P. R. China
| | - Jun He
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
- Wuhan Institute of Quantum Technology, Wuhan, 430206, P. R. China
- International College, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
- Hubei Luojia Laboratory, Wuhan, 430072, P. R. China
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24
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Wang H, Lu H, Guo Z, Li A, Wu P, Li J, Xie W, Sun Z, Li P, Damas H, Friedel AM, Migot S, Ghanbaja J, Moreau L, Fagot-Revurat Y, Petit-Watelot S, Hauet T, Robertson J, Mangin S, Zhao W, Nie T. Interfacial engineering of ferromagnetism in wafer-scale van der Waals Fe 4GeTe 2 far above room temperature. Nat Commun 2023; 14:2483. [PMID: 37120587 PMCID: PMC10148834 DOI: 10.1038/s41467-023-37917-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 04/05/2023] [Indexed: 05/01/2023] Open
Abstract
Despite recent advances in exfoliated vdW ferromagnets, the widespread application of 2D magnetism requires a Curie temperature (Tc) above room temperature as well as a stable and controllable magnetic anisotropy. Here we demonstrate a large-scale iron-based vdW material Fe4GeTe2 with the Tc reaching ~530 K. We confirmed the high-temperature ferromagnetism by multiple characterizations. Theoretical calculations suggested that the interface-induced right shift of the localized states for unpaired Fe d electrons is the reason for the enhanced Tc, which was confirmed by ultraviolet photoelectron spectroscopy. Moreover, by precisely tailoring Fe concentration we achieved arbitrary control of magnetic anisotropy between out-of-plane and in-plane without inducing any phase disorders. Our finding sheds light on the high potential of Fe4GeTe2 in spintronics, which may open opportunities for room-temperature application of all-vdW spintronic devices.
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Affiliation(s)
- Hangtian Wang
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Haichang Lu
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
- Engineering Department, Cambridge University, Cambridge, CB2 1PZ, UK.
| | - Zongxia Guo
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Ang Li
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Peichen Wu
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Jing Li
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Weiran Xie
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Zhimei Sun
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Peng Li
- Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, USA
| | - Héloïse Damas
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Anna Maria Friedel
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Sylvie Migot
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Jaafar Ghanbaja
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Luc Moreau
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | | | | | - Thomas Hauet
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - John Robertson
- Engineering Department, Cambridge University, Cambridge, CB2 1PZ, UK
| | - Stéphane Mangin
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France.
| | - Weisheng Zhao
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
| | - Tianxiao Nie
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
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25
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Zhao B, Ngaloy R, Ghosh S, Ershadrad S, Gupta R, Ali K, Hoque AM, Karpiak B, Khokhriakov D, Polley C, Thiagarajan B, Kalaboukhov A, Svedlindh P, Sanyal B, Dash SP. A Room-Temperature Spin-Valve with van der Waals Ferromagnet Fe 5 GeTe 2 /Graphene Heterostructure. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2209113. [PMID: 36641649 DOI: 10.1002/adma.202209113] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/07/2022] [Indexed: 06/17/2023]
Abstract
The discovery of van der Waals (vdW) magnets opened a new paradigm for condensed matter physics and spintronic technologies. However, the operations of active spintronic devices with vdW ferromagnets are limited to cryogenic temperatures, inhibiting their broader practical applications. Here, the robust room-temperature operation of lateral spin-valve devices using the vdW itinerant ferromagnet Fe5 GeTe2 in heterostructures with graphene is demonstrated. The room-temperature spintronic properties of Fe5 GeTe2 are measured at the interface with graphene with a negative spin polarization. Lateral spin-valve and spin-precession measurements provide unique insights by probing the Fe5 GeTe2 /graphene interface spintronic properties via spin-dynamics measurements, revealing multidirectional spin polarization. Density functional theory calculations in conjunction with Monte Carlo simulations reveal significantly canted Fe magnetic moments in Fe5 GeTe2 along with the presence of negative spin polarization at the Fe5 GeTe2 /graphene interface. These findings open opportunities for vdW interface design and applications of vdW-magnet-based spintronic devices at ambient temperatures.
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Affiliation(s)
- Bing Zhao
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
| | - Roselle Ngaloy
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
| | - Sukanya Ghosh
- Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden
| | - Soheil Ershadrad
- Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden
| | - Rahul Gupta
- Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden
- Department of Materials Science and Engineering, Uppsala University, Box 35, Uppsala, SE-751 03, Sweden
| | - Khadiza Ali
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
- MAX IV Laboratory, Lund University, Lund, SE-221 00, Sweden
| | - Anamul Md Hoque
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
| | - Bogdan Karpiak
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
| | - Dmitrii Khokhriakov
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
| | - Craig Polley
- MAX IV Laboratory, Lund University, Lund, SE-221 00, Sweden
| | | | - Alexei Kalaboukhov
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
| | - Peter Svedlindh
- Department of Materials Science and Engineering, Uppsala University, Box 35, Uppsala, SE-751 03, Sweden
| | - Biplab Sanyal
- Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden
| | - Saroj P Dash
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
- Graphene Center, Chalmers University of Technology, Göteborg, SE-41296, Sweden
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26
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Georgopoulou-Kotsaki E, Pappas P, Lintzeris A, Tsipas P, Fragkos S, Markou A, Felser C, Longo E, Fanciulli M, Mantovan R, Mahfouzi F, Kioussis N, Dimoulas A. Significant enhancement of ferromagnetism above room temperature in epitaxial 2D van der Waals ferromagnet Fe 5-δGeTe 2/Bi 2Te 3 heterostructures. NANOSCALE 2023; 15:2223-2233. [PMID: 36625389 DOI: 10.1039/d2nr04820e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Two-dimensional (2D) van der Waals (vdW) ferromagnetic metals FexGeTe2 with x = 3-5 have raised significant interest in the scientific community. Fe5GeTe2 shows prospects for spintronic applications since the Curie temperature Tc has been reported near or higher than 300 K. In the present work, epitaxial Fe5-δGeTe2 (FGT) heterostructures were grown by Molecular Beam Epitaxy (MBE) on insulating crystalline substrates. The FGT films were combined with Bi2Te3 topological insulator (TI) aiming to investigate the possible beneficial effect of the TI on the magnetic properties of FGT. FGT/Bi2Te3 films were compared to FGT capped only with AlOx to prevent oxidation. SQUID and MOKE measurements revealed that the growth of Bi2Te3 TI on FGT films significantly enhances the saturation magnetization of FGT as well as the Tc well above room temperature (RT) reaching record values of 570 K. First-principles calculations predict a shift of the Fermi level and an associated enhancement of the majority spin (primarily) as well as the total density of states at the Fermi level suggesting that effective doping of FGT from Bi2Te3 could explain the enhancement of ferromagnetism in FGT. It is also predicted that strain induced stabilization of a high magnetic moment phase in FGT/Bi2Te3 could be an alternative explanation of magnetization and Tc enhancement. Ferromagnetic resonance measurements evidence an enhanced broadening in the FGT/Bi2Te3 heterostructure when compared to FGT. We obtain a large spin mixing conductance of g↑↓eff = 4.4 × 1020 m-2, which demonstrates the great potential of FGT/Bi2Te3 systems for spin-charge conversion applications at room temperature.
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Affiliation(s)
- E Georgopoulou-Kotsaki
- National Centre for Scientific Research "Demokritos", Institute of Nanoscience and Nanotechnology, Agia Paraskevi, 15341, Athens, Greece.
- Section of Condensed Matter Physics, Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15784, Athens, Greece
| | - P Pappas
- National Centre for Scientific Research "Demokritos", Institute of Nanoscience and Nanotechnology, Agia Paraskevi, 15341, Athens, Greece.
| | - A Lintzeris
- National Centre for Scientific Research "Demokritos", Institute of Nanoscience and Nanotechnology, Agia Paraskevi, 15341, Athens, Greece.
- Department of Physics, National Technical University of Athens, School of Applied Mathematical and Physical Sciences, 15780, Athens, Greece
| | - P Tsipas
- National Centre for Scientific Research "Demokritos", Institute of Nanoscience and Nanotechnology, Agia Paraskevi, 15341, Athens, Greece.
| | - S Fragkos
- National Centre for Scientific Research "Demokritos", Institute of Nanoscience and Nanotechnology, Agia Paraskevi, 15341, Athens, Greece.
- Department of Mechanical Engineering, University of West Attica, 12241 Athens, Greece
| | - A Markou
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - C Felser
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - E Longo
- Institute for Microelectronics and Microsystems, CNR-IMM Unit of Agrate Brianza, Via C. Olivetti 2, 20864 Agrate Brianza, Italy
| | - M Fanciulli
- Department of Material Science, University of Milano Bicocca, Via R. Cozzi 55, Milan 20125, Italy
| | - R Mantovan
- Institute for Microelectronics and Microsystems, CNR-IMM Unit of Agrate Brianza, Via C. Olivetti 2, 20864 Agrate Brianza, Italy
| | - F Mahfouzi
- Department of Physics and Astronomy, California State University Northridge, Northridge, CA 91330-8268, USA
| | - N Kioussis
- Department of Physics and Astronomy, California State University Northridge, Northridge, CA 91330-8268, USA
| | - A Dimoulas
- National Centre for Scientific Research "Demokritos", Institute of Nanoscience and Nanotechnology, Agia Paraskevi, 15341, Athens, Greece.
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27
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Chen H, Asif S, Dolui K, Wang Y, Támara-Isaza J, Goli VMLDP, Whalen M, Wang X, Chen Z, Zhang H, Liu K, Jariwala D, Jungfleisch MB, Chakraborty C, May AF, McGuire MA, Nikolic BK, Xiao JQ, Ku MJH. Above-Room-Temperature Ferromagnetism in Thin van der Waals Flakes of Cobalt-Substituted Fe 5GeTe 2. ACS APPLIED MATERIALS & INTERFACES 2023; 15:3287-3296. [PMID: 36602594 DOI: 10.1021/acsami.2c18028] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Two-dimensional (2D) magnetic van der Waals materials provide a powerful platform for studying the fundamental physics of low-dimensional magnetism, engineering novel magnetic phases, and enabling thin and highly tunable spintronic devices. To realize high-quality and practical devices for such applications, there is a critical need for robust 2D magnets with ordering temperatures above room temperature that can be created via exfoliation. Here, the study of exfoliated flakes of cobalt-substituted Fe5GeTe2 (CFGT) exhibiting magnetism above room temperature is reported. Via quantum magnetic imaging with nitrogen-vacancy centers in diamond, ferromagnetism at room temperature was observed in CFGT flakes as thin as 16 nm corresponding to 16 layers. This result expands the portfolio of thin room-temperature 2D magnet flakes exfoliated from robust single crystals that reach a thickness regime relevant to practical spintronic applications. The Curie temperature Tc of CFGT ranges from 310 K in the thinnest flake studied to 328 K in the bulk. To investigate the prospect of high-temperature monolayer ferromagnetism, Monte Carlo calculations were performed, which predicted a high value of Tc of ∼270 K in CFGT monolayers. Pathways toward further enhancing monolayer Tc are discussed. These results support CFGT as a promising platform for realizing high-quality room-temperature 2D magnet devices.
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Affiliation(s)
- Hang Chen
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Shahidul Asif
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware19716, United States
| | - Kapildeb Dolui
- Lomare Technologies Ltd., 6 London Street, LondonEC3R 7LP, United Kingdom
| | - Yang Wang
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Jeyson Támara-Isaza
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
- Departamento de Física, Universidad Nacional de Colombia, Bogotá D.C.110851, Colombia
| | - V M L Durga Prasad Goli
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Matthew Whalen
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Xinhao Wang
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Zhijie Chen
- Department of Physics, Georgetown University, Washington, District of Columbia20057, United States
| | - Huiqin Zhang
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
| | - Kai Liu
- Department of Physics, Georgetown University, Washington, District of Columbia20057, United States
| | - Deep Jariwala
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
| | - M Benjamin Jungfleisch
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Chitraleema Chakraborty
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware19716, United States
| | - Andrew F May
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Michael A McGuire
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Branislav K Nikolic
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - John Q Xiao
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Mark J H Ku
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware19716, United States
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28
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O'Neill A, Rahman S, Zhang Z, Schoenherr P, Yildirim T, Gu B, Su G, Lu Y, Seidel J. Enhanced Room Temperature Ferromagnetism in Highly Strained 2D Semiconductor Cr 2Ge 2Te 6. ACS NANO 2023; 17:735-742. [PMID: 36546693 DOI: 10.1021/acsnano.2c10209] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Emergent magnetism in van der Waals materials offers exciting opportunities in fabricating atomically thin spintronic devices. One pertinent obstacle has been the low transition temperatures (Tc) inherent to these materials, precluding room temperature applications. Here, we show that large structural gradients found in highly strained nanoscale wrinkles in Cr2Ge2Te6 (CGT) lead to significant increases of Tc. Magnetic force microscopy was utilized in characterizing multiple strained CGT nanostructures leading to experimental evidence of elevated Tc, depending on the strain percentage estimated from finite element analysis. Our findings are further supported by ab initio and DFT studies of the strained material, which indicates that strain directly augments the ferromagnetic coupling between Cr atoms in CGT, influenced by superexchange interaction; this provides strong insight into the mechanism of the enhanced magnetism and Tc.
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Affiliation(s)
- Adam O'Neill
- School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW2052, Australia
| | - Sharidya Rahman
- School of Engineering, College of Science and Computer Science, The Australian National University, Canberra, ACT2601, Australia
| | - Zhen Zhang
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijng100049, China
| | - Peggy Schoenherr
- School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW2052, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), UNSW Sydney, Sydney, NSW2052, Australia
- CSIRO Mineral Resources, Lucas Heights, NSW2234, Australia
| | - Tanju Yildirim
- Center for Functional Sensor & Actuator (CFSN), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki305-0044, Japan
| | - Bo Gu
- Kavli Institute for Theoretical Sciences, and CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijng100190, China
- Physical Science Laboratory, Huairou National Comprehensive Science Center, Beijing101400, China
| | - Gang Su
- Kavli Institute for Theoretical Sciences, and CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijng100190, China
- Physical Science Laboratory, Huairou National Comprehensive Science Center, Beijing101400, China
| | - Yuerui Lu
- School of Engineering, College of Science and Computer Science, The Australian National University, Canberra, ACT2601, Australia
- ARC Centre of Excellence for Quantum Computation and Communication Technology, the Australian National University, Canberra, ACT2601, Australia
| | - Jan Seidel
- School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW2052, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), UNSW Sydney, Sydney, NSW2052, Australia
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29
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Wang L, Xiong J, Cheng B, Dai Y, Wang F, Pan C, Cao T, Liu X, Wang P, Chen M, Yan S, Liu Z, Xiao J, Xu X, Wang Z, Shi Y, Cheong SW, Zhang H, Liang SJ, Miao F. Cascadable in-memory computing based on symmetric writing and readout. SCIENCE ADVANCES 2022; 8:eabq6833. [PMID: 36490344 PMCID: PMC11324065 DOI: 10.1126/sciadv.abq6833] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 11/04/2022] [Indexed: 06/17/2023]
Abstract
The building block of in-memory computing with spintronic devices is mainly based on the magnetic tunnel junction with perpendicular interfacial anisotropy (p-MTJ). The resulting asymmetric write and readout operations impose challenges in downscaling and direct cascadability of p-MTJ devices. Here, we propose that a previously unimplemented symmetric write and readout mechanism can be realized in perpendicular-anisotropy spin-orbit (PASO) quantum materials based on Fe3GeTe2 and WTe2. We demonstrate that field-free and deterministic reversal of the perpendicular magnetization can be achieved using unconventional charge-to-z-spin conversion. The resulting magnetic state can be readily probed with its intrinsic inverse process, i.e., z-spin-to-charge conversion. Using the PASO quantum material as a fundamental building block, we implement the functionally complete set of logic-in-memory operations and a more complex nonvolatile half-adder logic function. Our work highlights the potential of PASO quantum materials for the development of scalable energy-efficient and ultrafast spintronic computing.
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Affiliation(s)
- Lizheng Wang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Junlin Xiong
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Bin Cheng
- Institute of Interdisciplinary Physical Sciences, School of Science, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yudi Dai
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Fuyi Wang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Chen Pan
- Institute of Interdisciplinary Physical Sciences, School of Science, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Tianjun Cao
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Xiaowei Liu
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Pengfei Wang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Moyu Chen
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Shengnan Yan
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Zenglin Liu
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jingjing Xiao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xianghan Xu
- Center for Quantum Materials Synthesis, and Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Zhenlin Wang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Youguo Shi
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Sang-Wook Cheong
- Center for Quantum Materials Synthesis, and Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Haijun Zhang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Shi-Jun Liang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Feng Miao
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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30
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Xue F, Zhang C, Ma Y, Wen Y, He X, Yu B, Zhang X. Integrated Memory Devices Based on 2D Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2201880. [PMID: 35557021 DOI: 10.1002/adma.202201880] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 05/07/2022] [Indexed: 06/15/2023]
Abstract
With the advent of the Internet of Things and big data, massive data must be rapidly processed and stored within a short timeframe. This imposes stringent requirements on memory hardware implementation in terms of operation speed, energy consumption, and integration density. To fulfill these demands, 2D materials, which are excellent electronic building blocks, provide numerous possibilities for developing advanced memory device arrays with high performance, smart computing architectures, and desirable downscaling. Over the past few years, 2D-material-based memory-device arrays with different working mechanisms, including defects, filaments, charges, ferroelectricity, and spins, have been increasingly developed. These arrays can be used to implement brain-inspired computing or sensing with extraordinary performance, architectures, and functionalities. Here, recent research into integrated, state-of-the-art memory devices made from 2D materials, as well as their implications for brain-inspired computing are surveyed. The existing challenges at the array level are discussed, and the scope for future research is presented.
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Affiliation(s)
- Fei Xue
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310020, P. R. China
- School of Micro-Nano Electronics, Zhejiang University, Hangzhou, 311200, P. R. China
| | - Chenhui Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Yinchang Ma
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Yan Wen
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Xin He
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Bin Yu
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310020, P. R. China
- School of Micro-Nano Electronics, Zhejiang University, Hangzhou, 311200, P. R. China
| | - Xixiang Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
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31
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Ma S, Li G, Li Z, Zhang Y, Lu H, Gao Z, Wu J, Long G, Huang Y. 2D Magnetic Semiconductor Fe 3GeTe 2 with Few and Single Layers with a Greatly Enhanced Intrinsic Exchange Bias by Liquid-Phase Exfoliation. ACS NANO 2022; 16:19439-19450. [PMID: 36288432 DOI: 10.1021/acsnano.2c09143] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A 2D van der Waals (vdW) magnet can get rid of the constraints of lattice matching and compatibility and then create a variety of vdW heterostructures, which provides a opportunity for spintronic devices. However, the ability to reliably exfoliate large, high-quality vdW ferromagnetic Fe3GeTe2 (FGT) nanoflakes in scaled-up production is severely limited. Herein, an efficient and stable three-stage sonication-assisted liquid-phase exfoliation was developed for mass preparation of high-structural-integrity few- and single-layer FGT nanoflakes with a greatly enhanced intrinsic exchange bias. The three stages include slicing crystals, weakening interlayer vdW forces, and using ultrasonic cavitation. The highest yield of FGT nanoflakes is 22.3 wt % with single layers accounting for 6%. The size is controllable, and several micrometers, tens of micrometers, and a maximum of 103 μm are available. The 200 mg level output has overcome the limitations of mechanical exfoliation and molecular beam epitaxy in economically amplificated production. An intrinsic exchange bias is observed in the restacked nanoflakes due to the magnetic proximity on the interface of the FGT/natural surface oxide layer. The material reaches 578 Oe (2 K) and 2300 Oe after further oxidation, at least 250% higher than other precisely tailored vdW magnetic heterostructures. In addition, the unusual semiconductivity of the liquid-phase exfoliated FGT nanoflakes is reported. This work skillfully utilizes oxidation to enhance the potential of FGT for large-scale spintronics, optoelectronics, efficient data storage, and various extended applications, and it is beneficial for exfoliating other promising magnetic vdW materials.
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Affiliation(s)
- Suping Ma
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
| | - Guanghao Li
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
| | - Zhuo Li
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
| | - Yawen Zhang
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
| | - Haolin Lu
- School of Materials Science and Engineering, National Institute for Advanced Materials, Renewable Energy Conversion and Storage Center (RECAST), Nankai University, Tianjin300350, People's Republic of China
| | - Zhansheng Gao
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
| | - Jinxiong Wu
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
- Beijing National Laboratory for Molecular Sciences, Beijing100871, People's Republic of China
| | - Guankui Long
- School of Materials Science and Engineering, National Institute for Advanced Materials, Renewable Energy Conversion and Storage Center (RECAST), Nankai University, Tianjin300350, People's Republic of China
| | - Yi Huang
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin300350, People's Republic of China
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32
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Ren H, Xiang G. Recent Progress in Research on Ferromagnetic Rhenium Disulfide. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3451. [PMID: 36234579 PMCID: PMC9565357 DOI: 10.3390/nano12193451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 09/26/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Since long-range magnetic ordering was observed in pristine Cr2Ge2Te6 and monolayer CrCl3, two-dimensional (2D) magnetic materials have gradually become an emerging field of interest. However, it is challenging to induce and modulate magnetism in non-magnetic (NM) materials such as rhenium disulfide (ReS2). Theoretical research shows that defects, doping, strain, particular phase, and domain engineering may facilitate the creation of magnetic ordering in the ReS2 system. These predictions have, to a large extent, stimulated experimental efforts in the field. Herein, we summarize the recent progress on ferromagnetism (FM) in ReS2. We compare the proposed methods to introduce and modulate magnetism in ReS2, some of which have made great experimental breakthroughs. Experimentally, only a few ReS2 materials exhibit room-temperature long-range ferromagnetic order. In addition, the superexchange interaction may cause weak ferromagnetic coupling between neighboring trimers. We also present a few potential research directions for the future, and we finally conclude that a deep and thorough understanding of the origin of FM with and without strain is very important for the development of basic research and practical applications.
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Affiliation(s)
- Hongtao Ren
- School of Materials Science and Engineering, Liaocheng University, Hunan Road No. 1, Liaocheng 252000, China
| | - Gang Xiang
- College of Physics, Sichuan University, Wangjiang Road No. 29, Chengdu 610064, China
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33
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Dai H, Cai M, Hao Q, Liu Q, Xing Y, Chen H, Chen X, Wang X, Fu HH, Han J. Nonlocal Manipulation of Magnetism in an Itinerant Two-Dimensional Ferromagnet. ACS NANO 2022; 16:12437-12444. [PMID: 35900014 DOI: 10.1021/acsnano.2c03626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Two-dimensional (2D) magnets are crucial in the construction of 2D magnetic and spintronic devices. Many devices, including spin valves and multiple tunneling junctions, have been developed by vertically stacking 2D magnets with other functional blocks. However, owing to limited local interactions at the interfaces, the device structures are typically extremely complex. To solve this problem, the nonlocal manipulation of magnetism may be a good solution. In this study, we use the magneto-optical Kerr effect technique to demonstrate the nonlocal manipulation of magnetism in an itinerant 2D ferromagnet, Fe3GeTe2 (FGT), whose magnetism can be manipulated via an antiferromagnet/ferromagnet interface or a current-induced spin-orbital torque placed distant from the local site. It is discovered that the coupling of a small piece of MnPS3 (∼40 μm2) with FGT can significantly enhance the coercive field and emergence of exchange bias in the entire FGT flake (∼2000 μm2). Moreover, FGT flakes with different thicknesses have the same coercive field at low temperatures if they are coupled together. Our study provides an understanding of the basic magnetism of 2D itinerant ferromagnets as well as opportunities for engineering magnetism with an additional degree of freedom.
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Affiliation(s)
- Hongwei Dai
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
- Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Menghao Cai
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
- Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Qinghua Hao
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
- Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Qingbo Liu
- Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Yuntong Xing
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
- Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Hongjing Chen
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
- Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Xiaodie Chen
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
- Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Xia Wang
- School of Elementary Education, Wuhan City Polytechnic College, Wuhan, 430070, China
| | - Hua-Hua Fu
- Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Junbo Han
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
- Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
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34
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Zhu W, Song C, Wang Q, Bai H, Yin S, Pan F. Anomalous displacement reaction for synthesizing above-room-temperature and air-stable vdW ferromagnet PtTe 2Ge 1/3. Natl Sci Rev 2022; 10:nwac173. [PMID: 36684515 PMCID: PMC9843128 DOI: 10.1093/nsr/nwac173] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 08/10/2022] [Indexed: 01/25/2023] Open
Abstract
Emerging van der Waals (vdW) magnets provide a paradise for the exploration of magnetism in the ultimate two-dimensional (2D) limit, and the construction of integrated spintronic devices, and have become a research frontier in the field of low-dimensional materials. To date, prototypical vdW magnets based on metals of the first transition series (e.g. V, Cr, Mn and Fe) and chalcogen elements suffer from rapid oxidation restricted by the Hard-Soft-Acid-Base principle, as well as low Curie temperatures (T C), which has become a generally admitted challenge in 2D spintronics. Here, starting from air-unstable Cr2Ge2Te6 vdW thin flakes, we synthesize Ge-embedded PtTe2 (namely PtTe2Ge1/3) with superior air stability, through the displacement reaction in the Cr2Ge2Te6/Pt bilayer. In this process, the anomalous substitution of Cr with Pt in the thermal diffusion is inverse to the metal activity order, which can be attributed to the compatibility between soft-acid (Pt) and soft-base (Te) elements. Meanwhile, the layered uniform insertion of Ge unbalances Pt-Te bonds and introduces long-range ordered ferromagnetism with perpendicular magnetic anisotropy and a Curie temperature above room temperature. Our work demonstrates the anti-metal-activity-order reaction tendency unique in 2D transition-metal magnets and boosts progress towards practical 2D spintronics.
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Affiliation(s)
- Wenxuan Zhu
- Key Laboratory of Advanced Materials, School of Materials Science and Engineering, Beijing Innovation Center for Future Chips, Tsinghua University, Beijing 100084, China
| | | | - Qian Wang
- Key Laboratory of Advanced Materials, School of Materials Science and Engineering, Beijing Innovation Center for Future Chips, Tsinghua University, Beijing 100084, China
| | - Hua Bai
- Key Laboratory of Advanced Materials, School of Materials Science and Engineering, Beijing Innovation Center for Future Chips, Tsinghua University, Beijing 100084, China
| | - Siqi Yin
- Key Laboratory of Advanced Materials, School of Materials Science and Engineering, Beijing Innovation Center for Future Chips, Tsinghua University, Beijing 100084, China
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35
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Wang QH, Bedoya-Pinto A, Blei M, Dismukes AH, Hamo A, Jenkins S, Koperski M, Liu Y, Sun QC, Telford EJ, Kim HH, Augustin M, Vool U, Yin JX, Li LH, Falin A, Dean CR, Casanova F, Evans RFL, Chshiev M, Mishchenko A, Petrovic C, He R, Zhao L, Tsen AW, Gerardot BD, Brotons-Gisbert M, Guguchia Z, Roy X, Tongay S, Wang Z, Hasan MZ, Wrachtrup J, Yacoby A, Fert A, Parkin S, Novoselov KS, Dai P, Balicas L, Santos EJG. The Magnetic Genome of Two-Dimensional van der Waals Materials. ACS NANO 2022; 16:6960-7079. [PMID: 35442017 PMCID: PMC9134533 DOI: 10.1021/acsnano.1c09150] [Citation(s) in RCA: 70] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 02/23/2022] [Indexed: 05/23/2023]
Abstract
Magnetism in two-dimensional (2D) van der Waals (vdW) materials has recently emerged as one of the most promising areas in condensed matter research, with many exciting emerging properties and significant potential for applications ranging from topological magnonics to low-power spintronics, quantum computing, and optical communications. In the brief time after their discovery, 2D magnets have blossomed into a rich area for investigation, where fundamental concepts in magnetism are challenged by the behavior of spins that can develop at the single layer limit. However, much effort is still needed in multiple fronts before 2D magnets can be routinely used for practical implementations. In this comprehensive review, prominent authors with expertise in complementary fields of 2D magnetism (i.e., synthesis, device engineering, magneto-optics, imaging, transport, mechanics, spin excitations, and theory and simulations) have joined together to provide a genome of current knowledge and a guideline for future developments in 2D magnetic materials research.
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Affiliation(s)
- Qing Hua Wang
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Amilcar Bedoya-Pinto
- NISE
Department, Max Planck Institute of Microstructure
Physics, 06120 Halle, Germany
- Instituto
de Ciencia Molecular (ICMol), Universitat
de València, 46980 Paterna, Spain
| | - Mark Blei
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Avalon H. Dismukes
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Assaf Hamo
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Sarah Jenkins
- Twist
Group,
Faculty of Physics, University of Duisburg-Essen, Campus Duisburg, 47057 Duisburg, Germany
| | - Maciej Koperski
- Institute
for Functional Intelligent Materials, National
University of Singapore, 117544 Singapore
| | - Yu Liu
- Condensed
Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Qi-Chao Sun
- Physikalisches
Institut, University of Stuttgart, 70569 Stuttgart, Germany
| | - Evan J. Telford
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
- Department
of Physics, Columbia University, New York, New York 10027, United States
| | - Hyun Ho Kim
- School
of Materials Science and Engineering, Department of Energy Engineering
Convergence, Kumoh National Institute of
Technology, Gumi 39177, Korea
| | - Mathias Augustin
- Institute
for Condensed Matter Physics and Complex Systems, School of Physics
and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
| | - Uri Vool
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
- John Harvard
Distinguished Science Fellows Program, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - Jia-Xin Yin
- Laboratory
for Topological Quantum Matter and Spectroscopy, Department of Physics, Princeton University, Princeton, New Jersey 08544, United States
| | - Lu Hua Li
- Institute
for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Waurn Ponds, Victoria 3216, Australia
| | - Alexey Falin
- Institute
for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Waurn Ponds, Victoria 3216, Australia
| | - Cory R. Dean
- Department
of Physics, Columbia University, New York, New York 10027, United States
| | - Fèlix Casanova
- CIC nanoGUNE
BRTA, 20018 Donostia - San Sebastián, Basque
Country, Spain
- IKERBASQUE,
Basque Foundation for Science, 48013 Bilbao, Basque Country, Spain
| | - Richard F. L. Evans
- Department
of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Mairbek Chshiev
- Université
Grenoble Alpes, CEA, CNRS, Spintec, 38000 Grenoble, France
- Institut
Universitaire de France, 75231 Paris, France
| | - Artem Mishchenko
- Department
of Physics and Astronomy, University of
Manchester, Manchester, M13 9PL, United Kingdom
- National
Graphene Institute, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Cedomir Petrovic
- Condensed
Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Rui He
- Department
of Electrical and Computer Engineering, Texas Tech University, 910 Boston Avenue, Lubbock, Texas 79409, United
States
| | - Liuyan Zhao
- Department
of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109, United States
| | - Adam W. Tsen
- Institute
for Quantum Computing and Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Brian D. Gerardot
- SUPA, Institute
of Photonics and Quantum Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, United Kingdom
| | - Mauro Brotons-Gisbert
- SUPA, Institute
of Photonics and Quantum Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, United Kingdom
| | - Zurab Guguchia
- Laboratory
for Muon Spin Spectroscopy, Paul Scherrer
Institute, CH-5232 Villigen PSI, Switzerland
| | - Xavier Roy
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Sefaattin Tongay
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Ziwei Wang
- Department
of Physics and Astronomy, University of
Manchester, Manchester, M13 9PL, United Kingdom
- National
Graphene Institute, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - M. Zahid Hasan
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Princeton
Institute for Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
| | - Joerg Wrachtrup
- Physikalisches
Institut, University of Stuttgart, 70569 Stuttgart, Germany
- Max Planck
Institute for Solid State Research, 70569 Stuttgart, Germany
| | - Amir Yacoby
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
- John A.
Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Albert Fert
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Unité
Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
- Department
of Materials Physics UPV/EHU, 20018 Donostia - San Sebastián, Basque Country, Spain
| | - Stuart Parkin
- NISE
Department, Max Planck Institute of Microstructure
Physics, 06120 Halle, Germany
| | - Kostya S. Novoselov
- Institute
for Functional Intelligent Materials, National
University of Singapore, 117544 Singapore
| | - Pengcheng Dai
- Department
of Physics and Astronomy, Rice University, Houston, Texas 77005, United States
| | - Luis Balicas
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
- Department
of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Elton J. G. Santos
- Institute
for Condensed Matter Physics and Complex Systems, School of Physics
and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Higgs Centre
for Theoretical Physics, The University
of Edinburgh, Edinburgh EH9 3FD, United Kingdom
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36
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Li G, Ma S, Li Z, Zhang Y, Diao J, Xia L, Zhang Z, Huang Y. High-Quality Ferromagnet Fe 3GeTe 2 for High-Efficiency Electromagnetic Wave Absorption and Shielding with Wideband Radar Cross Section Reduction. ACS NANO 2022; 16:7861-7879. [PMID: 35467351 DOI: 10.1021/acsnano.2c00512] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A high-quality Fe3GeTe2 single crystal with good electrical, magnetic, and electromagnetic wave absorption and shielding properties was prepared in a large quantity (10 g level) by solid-phase sintering and recrystallization method, which would promote its in-depth research and practical application. It has good room-temperature electrical properties with a mobility of 42 cm2/V·s, a sheet (bulk) carrier concentration of +1.64 × 1018 /cm2 (+3.28 × 1020 /cm3), and a conductivity of 2196.35 S/cm. Also, a Curie temperature of 238 K indicates the high magnetic transition temperature and a paramagnetic Curie temperature of 301 K shows the large ferromagnetic-paramagnetic transition zone induced by the residual short-range ferromagnetic domains. Particularly, Fe3GeTe2 is in a loosely packed state when used as a loss agent; the electromagnetic wave absorption with a reflection loss of -34.7 dB at 3.66 GHz under thin thickness was shown. Meanwhile, the absorption band can be effectively regulated by varying the thickness. Moreover, Fe3GeTe2 in a close-packed state exhibits terahertz shielding values of 75.1 and 103.2 dB at very thin thicknesses of 70 and 380 μm, and the average shielding value is higher than 47 dB, covering the entire bandwidth from 0.1 to 3.0 THz. Furthermore, by using Fe3GeTe2 as a patch, the wideband radar cross-section can be effectively reduced by up to 33 dBsm. Resultantly, Fe3GeTe2 will be a promising candidate in the electromagnetic protection field.
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Affiliation(s)
- Guanghao Li
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Suping Ma
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Zhuo Li
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Yawen Zhang
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Jianglin Diao
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Lun Xia
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Zhiwei Zhang
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Yi Huang
- National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, Key Laboratory of Functional Polymer Materials, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
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37
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Wu Y, Wang W, Pan L, Wang KL. Manipulating Exchange Bias in a Van der Waals Ferromagnet. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2105266. [PMID: 34910836 DOI: 10.1002/adma.202105266] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 12/01/2021] [Indexed: 06/14/2023]
Abstract
Spintronics applications of thin-film magnets require control and design of specific magnetic properties. Exchange bias, originating from the pinning of spins in a ferromagnet by these of an antiferromagnet, is a part of the highly important elements for spintronics applications. Here, an exchange bias of ≈90 mT in a van der Waals ferromagnet encapsulated by two antiferromagnets at 5 K, the value of which is highly tunable by the field coolings, is reported. The non-antisymmetric dependence of exchange bias on field cooling is explained through considering an uncompensated interfacial magnetic layer of an antiferromagnet with a noncollinear spin texture, and a weak antiferromagnetic order in the oxidized layer, at two ferromagnet/antiferromagnet interfaces. This work opens up new routes toward designing and controlling 2D spintronic devices made of atomically thin van der Waals magnets.
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Affiliation(s)
- Yingying Wu
- Department of Electrical and Computer Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Wei Wang
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Lei Pan
- Department of Electrical and Computer Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Kang L Wang
- Department of Electrical and Computer Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
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38
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Chen X, Wang H, Liu H, Wang C, Wei G, Fang C, Wang H, Geng C, Liu S, Li P, Yu H, Zhao W, Miao J, Li Y, Wang L, Nie T, Zhao J, Wu X. Generation and Control of Terahertz Spin Currents in Topology-Induced 2D Ferromagnetic Fe 3 GeTe 2 |Bi 2 Te 3 Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2106172. [PMID: 34816497 DOI: 10.1002/adma.202106172] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 11/10/2021] [Indexed: 06/13/2023]
Abstract
Future information technologies for low-dissipation quantum computation, high-speed storage, and on-chip communication applications require the development of atomically thin, ultracompact, and ultrafast spintronic devices in which information is encoded, stored, and processed using electron spin. Exploring low-dimensional magnetic materials, designing novel heterostructures, and generating and controlling ultrafast electron spin in 2D magnetism at room temperature, preferably in the unprecedented terahertz (THz) regime, is in high demand. Using THz emission spectroscopy driven by femtosecond laser pulses, optical THz spin-current bursts at room temperature in the 2D van der Waals ferromagnetic Fe3 GeTe2 (FGT) integrated with Bi2 Te3 as a topological insulator are successfully realized. The symmetry of the THz radiation is effectively controlled by the optical pumping incidence and external magnetic field directions, indicating that the THz generation mechanism is the inverse Edelstein effect contributed spin-to-charge conversion. Thickness-, temperature-, and structure-dependent nontrivial THz transients reveal that topology-enhanced interlayer exchange coupling increases the FGT Curie temperature to room temperature, which provides an effective approach for engineering THz spin-current pulses. These results contribute to the goal of all-optical generation, manipulation, and detection of ultrafast THz spin currents in room-temperature 2D magnetism, accelerating the development of atomically thin high-speed spintronic devices.
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Affiliation(s)
- Xinhou Chen
- School of Electronic and Information Engineering, Beihang University, Beijing, 100191, China
| | - Hangtian Wang
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Haijiang Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Chun Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gaoshuai Wei
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chan Fang
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Hanchen Wang
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Chunyan Geng
- School of Electronic and Information Engineering, Beihang University, Beijing, 100191, China
| | - Shaojie Liu
- School of Cyber Science and Technology, Beihang University, Beijing, 100191, China
| | - Peiyan Li
- School of Electronic and Information Engineering, Beihang University, Beijing, 100191, China
| | - Haiming Yu
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Weisheng Zhao
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Hefei Innovation Research Institute, Beihang University, Hefei, 230013, China
| | - Jungang Miao
- School of Electronic and Information Engineering, Beihang University, Beijing, 100191, China
| | - Yutong Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, 523808, China
| | - Li Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Tianxiao Nie
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Hefei Innovation Research Institute, Beihang University, Hefei, 230013, China
| | - Jimin Zhao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, 523808, China
| | - Xiaojun Wu
- School of Electronic and Information Engineering, Beihang University, Beijing, 100191, China
- School of Cyber Science and Technology, Beihang University, Beijing, 100191, China
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
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Lin H, Luo X, Liu L, Wang D, Zhao X, Wang Z, Xue X, Zhang F, Xing G. All-Electrical Control of Compact SOT-MRAM: Toward Highly Efficient and Reliable Non-Volatile In-Memory Computing. MICROMACHINES 2022; 13:319. [PMID: 35208443 PMCID: PMC8876745 DOI: 10.3390/mi13020319] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 02/01/2023]
Abstract
Two-dimensional van der Waals (2D vdW) ferromagnets possess outstanding scalability, controllable ferromagnetism, and out-of-plane anisotropy, enabling the compact spintronics-based non-volatile in-memory computing (nv-IMC) that promises to tackle the memory wall bottleneck issue. Here, by employing the intriguing room-temperature ferromagnetic characteristics of emerging 2D Fe3GeTe2 with the dissimilar electronic structure of the two spin-conducting channels, we report on a new type of non-volatile spin-orbit torque (SOT) magnetic tunnel junction (MTJ) device based on Fe3GeTe2/MgO/Fe3GeTe2 heterostructure, which demonstrates the uni-polar and high-speed field-free magnetization switching by adjusting the ratio of field-like torque to damping-like torque coefficient in the free layer. Compared to the conventional 2T1M structure, the developed 3-transistor-2-MTJ (3T2M) cell is implemented with the complementary data storage feature and the enhanced sensing margin of 201.4% (from 271.7 mV to 547.2 mV) and 276% (from 188.2 mV to 520 mV) for reading "1" and "0", respectively. Moreover, superior to the traditional CoFeB-based MTJ memory cell counterpart, the 3T2M crossbar array architecture can be executed for AND/NAND, OR/NOR Boolean logic operation with a fast latency of 24 ps and ultra-low power consumption of 2.47 fJ/bit. Such device to architecture design with elaborated micro-magnetic and circuit-level simulation results shows great potential for realizing high-performance 2D material-based compact SOT magnetic random-access memory, facilitating new applications of highly reliable and energy-efficient nv-IMC.
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Affiliation(s)
- Huai Lin
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (H.L.); (L.L.); (D.W.); (X.Z.); (Z.W.); (F.Z.)
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xi Luo
- Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081, China;
| | - Long Liu
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (H.L.); (L.L.); (D.W.); (X.Z.); (Z.W.); (F.Z.)
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Di Wang
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (H.L.); (L.L.); (D.W.); (X.Z.); (Z.W.); (F.Z.)
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xuefeng Zhao
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (H.L.); (L.L.); (D.W.); (X.Z.); (Z.W.); (F.Z.)
- School of Microelectronics, University of Science and Technology of China, Hefei 230026, China
| | - Ziwei Wang
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (H.L.); (L.L.); (D.W.); (X.Z.); (Z.W.); (F.Z.)
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyong Xue
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 201203, China;
| | - Feng Zhang
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (H.L.); (L.L.); (D.W.); (X.Z.); (Z.W.); (F.Z.)
| | - Guozhong Xing
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (H.L.); (L.L.); (D.W.); (X.Z.); (Z.W.); (F.Z.)
- University of the Chinese Academy of Sciences, Beijing 100049, China
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40
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Lin H, Yan F, Hu C, Zheng Y, Sheng Y, Zhu W, Wang Z, Zheng H, Wang K. Current-assisted magnetization reversal in Fe 3GeTe 2 van der Waals homojunctions. NANOSCALE 2022; 14:2352-2358. [PMID: 35088803 DOI: 10.1039/d1nr07730a] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Among the numerous two-dimensional van der Waals (vdW) magnetic materials, Fe3GeTe2 (FGT), due to its outstanding properties such as metallicity, high Curie temperature and strong perpendicular magnetic anisotropy, has quickly emerged as a candidate with the most potential for the fabrication of all-vdW spintronic devices. Here, we fabricated a simple vertical homojunction based on two few-layer exfoliated FGT flakes. Under a certain range of external magnetic fields, the magnetization reversal can be achieved by applying a negative or positive pulse current, which can reduce the coercivity through the spin orbit torque of FGT itself in addition to the Joule heat. Moreover, the asymmetrical switching current is caused by the spin transfer torque in the homojunction. As the temperature increases, the magnetization reversal can be observed at a smaller external magnetic field. Our demonstrations of the current-assisted magnetization reversal under a magnetic field in all-vdW structures may provide support for the potential application of vdW magnetism.
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Affiliation(s)
- Hailong Lin
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Faguang Yan
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
| | - Ce Hu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuanhui Zheng
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Yu Sheng
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
| | - Wenkai Zhu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ziao Wang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Houzhi Zheng
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kaiyou Wang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
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41
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Peng B, Chen Z, Li Y, Liu Z, Liang D, Deng L. Multiwavelength magnetic coding of helical luminescence in ferromagnetic 2D layered CrI 3. iScience 2022; 25:103623. [PMID: 35005559 PMCID: PMC8718829 DOI: 10.1016/j.isci.2021.103623] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 11/15/2021] [Accepted: 12/10/2021] [Indexed: 11/01/2022] Open
Abstract
Two-dimensional (2D) van der Waals (vdW) ferromagnets have opened new avenues for manipulating spin at the limits of single or few atomic layers, and for creating unique magneto-exciton devices through the coupling of ferromagnetic (FM) orders and excitons. However, 2D vdW ferromagnets explored so far have rarely possessed exciton behaviors; to date, FM CrI3 have been revealed to show ligand-field photoluminescence correlated with FM ordering, but typically with a broad emission peak. Here, we report a straightforward approach to realize strong coupling of narrow helical emission and FM orders in CrI3 through microsphere cavity. The resonant whispering-gallery modes (WGM) of SiO2 microspheres cause strong oscillation helical emissions with a full width at half-maximum (FWHM) of ∼5 nm under continuous wave excitation. Reversible magnetic coding of helical luminescence is realized in the range of 950-1100 nm. This work enables numerous opportunities for creating magnetic encoding lasing for photonic integrated chips.
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Affiliation(s)
- Bo Peng
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.,State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Zhiyong Chen
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.,State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yue Li
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.,State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Zhen Liu
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.,State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Difei Liang
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.,State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Longjiang Deng
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.,State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China
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42
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Liu KL, Luo MB, Zhou X, Lin Q. Cationic complex directed thiostannate layers with excellent proton conduction and photocatalysis properties. CrystEngComm 2022. [DOI: 10.1039/d2ce00043a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three isostructural thiostannates SnS-M (M = Fe, Mn and Zn) have been fabricated using metal-amine complex cations as structure-directing agents. These thiostannates are composed of typical two-dimensional lamellar [Sn3S7]n2n- anionic...
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43
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Hu L, Zhou J, Hou Z, Su W, Yang B, Li L, Yan M. Polymer-buried van der Waals magnets for promising wearable room-temperature spintronics. MATERIALS HORIZONS 2021; 8:3306-3314. [PMID: 34751291 DOI: 10.1039/d1mh01439k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The demand for high-performance spintronic devices has boosted intense research on the manipulation of magnetism in van der Waals (vdW) magnets. Despite great efforts, robust ferromagnetic transitions above room temperature still face significant hurdles. Strain engineering can reversibly regulate magnetic exchange, but the degree of regulation is still impractical for most magnetic applications. Hereby we employ a large-strain transferrer to produce tunable strains of up to 4.7%, which induces authentic room-temperature ferromagnetism in large-area Fe3GeTe2 nanoflakes with 20-fold improvement in magnetization. The record increment of the Curie temperature (TC) of well above 400 K originates from the strain-enhanced magnetic anisotropy and excellent magnetoelastic coupling. The correlation between the emerging ferromagnetism and Raman spectral evolution is also established, which complements well the TC phase diagram in a large-strain region. In addition, an unusual exchange bias effect with a vertical magnetization shift is tracked for the first time upon bending, which reveals the hidden competition between antiferromagnetic and ferromagnetic coupling. The reversible strain manipulation of single-domain ferromagnetic order in a single nanoflake further opens up a route to develop low-power wearable spintronic devices. The findings here provide vast opportunities to exploit the possibility of practical applications of more vdW magnets.
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Affiliation(s)
- Liang Hu
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
- State Key Lab of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China
| | - Jian Zhou
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
| | - Zhipeng Hou
- South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China
| | - Weitao Su
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
| | - Bingzhang Yang
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
| | - Lingwei Li
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
| | - Mi Yan
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
- State Key Lab of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China
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44
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Rahman S, Torres JF, Khan AR, Lu Y. Recent Developments in van der Waals Antiferromagnetic 2D Materials: Synthesis, Characterization, and Device Implementation. ACS NANO 2021; 15:17175-17213. [PMID: 34779616 DOI: 10.1021/acsnano.1c06864] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Magnetism in two dimensions is one of the most intriguing and alluring phenomena in condensed matter physics. Atomically thin 2D materials have emerged as a promising platform for exploring magnetic properties, leading to the development of essential technologies such as supercomputing and data storage. Arising from spin and charge dynamics in elementary particles, magnetism has also unraveled promising advances in spintronic devices and spin-dependent optoelectronics and photonics. Recently, antiferromagnetism in 2D materials has received extensive attention, leading to significant advances in their understanding and emerging applications; such materials have zero net magnetic moment yet are internally magnetic. Several theoretical and experimental approaches have been proposed to probe, characterize, and modulate the magnetic states efficiently in such systems. This Review presents the latest developments and current status for tuning the magnetic properties in distinct 2D van der Waals antiferromagnets. Various state-of-the-art optical techniques deployed to investigate magnetic textures and dynamics are discussed. Furthermore, device concepts based on antiferromagnetic spintronics are scrutinized. We conclude with remarks on related challenges and technological outlook in this rapidly expanding field.
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Affiliation(s)
- Sharidya Rahman
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Juan F Torres
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Ahmed Raza Khan
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Yuerui Lu
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia
- ARC Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Acton, ACT 2601, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), ANU node, Canberra, ACT 2601, Australia
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45
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Chen Q, Liang J, Fang B, Zhu Y, Wang J, Lv W, Lv W, Cai J, Huang Z, Zhai Y, Zhang B, Zeng Z. Proximity effect of a two-dimensional van der Waals magnet Fe 3GeTe 2 on nickel films. NANOSCALE 2021; 13:14688-14693. [PMID: 34533556 DOI: 10.1039/d1nr03342e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Recent advances in two-dimensional van der Waals (2D vdW) magnets provide new platforms to study their magnetism in reduced dimensions. However, most of the studies performed to date have been limited to low temperatures. Here, we report the proximity effect of a 2D vdW magnet Fe3GeTe2 (FGT) on nickel (Ni) films at room temperature. Ferromagnetic resonance measurements show that FGT can increase the perpendicular magnetic anisotropy (PMA) and magnetic damping of the adjacent Ni film. Such an interfacial effect is observed at room temperature, and becomes more pronounced as the temperature decreases. A similar effect is also achieved in another 2D heterostructure of Cr2Ge2Te6/Ni, implying its universality in a variety of 2D magnetic materials. Our work provides a new approach for utilizing 2D magnets in spintronics at room temperature.
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Affiliation(s)
- Qian Chen
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
| | - Jian Liang
- School of Physics, Southeast University, Nanjing, Jiangsu, 211189, China.
| | - Bin Fang
- Nanchang Nano-Devices and Technologies Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Nanchang, Jiangxi, 330200, China
| | - Yonghui Zhu
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
- School of Physics, Southeast University, Nanjing, Jiangsu, 211189, China.
| | - Jiachen Wang
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
| | - Weiming Lv
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
- Nanchang Nano-Devices and Technologies Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Nanchang, Jiangxi, 330200, China
| | - Wenxing Lv
- Physics Laboratory, Industrial Training Center, Shenzhen Polytechnic, Shenzhen, Guangdong, 518055, China
| | - Jialin Cai
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
- Nanchang Nano-Devices and Technologies Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Nanchang, Jiangxi, 330200, China
| | - Zhaocong Huang
- School of Physics, Southeast University, Nanjing, Jiangsu, 211189, China.
| | - Ya Zhai
- School of Physics, Southeast University, Nanjing, Jiangsu, 211189, China.
| | - Baoshun Zhang
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
| | - Zhongming Zeng
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
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Tang W, Liu H, Li Z, Pan A, Zeng Y. Spin-Orbit Torque in Van der Waals-Layered Materials and Heterostructures. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2100847. [PMID: 34323390 PMCID: PMC8456225 DOI: 10.1002/advs.202100847] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 06/03/2021] [Indexed: 06/13/2023]
Abstract
Spin-orbit torque (SOT) opens an efficient and versatile avenue for the electrical manipulation of magnetization in spintronic devices. The enhancement of SOT efficiency and reduction of power consumption are key points for the implementation of high-performance SOT devices, which strongly rely on the spin-orbit coupling (SOC) strength and magnetic properties of ferromagnetic/non-magnetic heterostructures. Recently, van der Waals-layered materials have shown appealing properties for use in efficient SOT applications. On the one hand, transition-metal dichalcogenides, topological insulators, and graphene-based heterostructures possess appreciable SOC strength. This feature can efficiently converse the charge current into spin current and result in large SOT. On the other hand, the newly discovered layered magnetic materials provide ultra-thin and gate-tunable ferromagnetic candidates for high-performance SOT devices. In this review, the latest advancements of SOT research in various layered materials are summarized. First, a brief introduction of SOT is given. Second, SOT studies of various layered materials and heterostructures are summarized. Subsequently, progresses on SOT-induced magnetization switching are presented. Finally, current challenges and prospects for future development are suggested.
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Affiliation(s)
- Wei Tang
- Key laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China
| | - Haoliang Liu
- State Key Laboratory on Tunable Laser TechnologyMinistry of Industry and Information Technology Key Lab of Micro‐Nano Optoelectronic Information SystemSchool of ScienceHarbin Institute of TechnologyShenzhen518055China
| | - Zhe Li
- State Key Laboratory on Tunable Laser TechnologyMinistry of Industry and Information Technology Key Lab of Micro‐Nano Optoelectronic Information SystemSchool of ScienceHarbin Institute of TechnologyShenzhen518055China
| | - Anlian Pan
- Key Laboratory for Micro‐Nano Physics and Technology of Hunan ProvinceCollege of Materials Science and EngineeringHunan UniversityChangsha410082China
| | - Yu‐Jia Zeng
- Key laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China
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47
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Tian M, Zhu Y, Jalali M, Jiang W, Liang J, Huang Z, Chen Q, Zeng Z, Zhai Y. Two-Dimensional Van Der Waals Materials for Spin-Orbit Torque Applications. FRONTIERS IN NANOTECHNOLOGY 2021. [DOI: 10.3389/fnano.2021.732916] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Spin-orbit torque (SOT) provides an efficient approach to control the magnetic state and dynamics in different classes of materials. Recent years, the crossover between two-dimensional van der Waals (2D vdW) materials and SOT opens a new prospect to push SOT devices to the 2D limit. In this mini-review, we summarize the latest progress in 2D vdW materials for SOT applications, highlighting the comparison of the performance between devices with various structures. It is prospected that the large family of 2D vdW materials and numerous combinations of heterostructures will widely extend the material choices and bring new opportunities to SOT devices in the future.
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Bhattacharyya S, Akhgar G, Gebert M, Karel J, Edmonds MT, Fuhrer MS. Recent Progress in Proximity Coupling of Magnetism to Topological Insulators. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2007795. [PMID: 34185344 DOI: 10.1002/adma.202007795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/11/2021] [Indexed: 05/08/2023]
Abstract
Inducing long-range magnetic order in 3D topological insulators can gap the Dirac-like metallic surface states, leading to exotic new phases such as the quantum anomalous Hall effect or the axion insulator state. These magnetic topological phases can host robust, dissipationless charge and spin currents or unique magnetoelectric behavior, which can be exploited in low-energy electronics and spintronics applications. Although several different strategies have been successfully implemented to realize these states, to date these phenomena have been confined to temperatures below a few Kelvin. This review focuses on one strategy: inducing magnetic order in topological insulators by proximity of magnetic materials, which has the capability for room temperature operation, unlocking the potential of magnetic topological phases for applications. The unique advantages of this strategy, the important physical mechanisms facilitating magnetic proximity effect, and the recent progress to achieve, understand, and harness proximity-coupled magnetic order in topological insulators are discussed. Some emerging new phenomena and applications enabled by proximity coupling of magnetism and topological materials, such as skyrmions and the topological Hall effect, are also highlighted, and the authors conclude with an outlook on remaining challenges and opportunities in the field.
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Affiliation(s)
- Semonti Bhattacharyya
- School of Physics and Astronomy, Monash University, Victoria, 3800, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria, 3800, Australia
| | - Golrokh Akhgar
- School of Physics and Astronomy, Monash University, Victoria, 3800, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria, 3800, Australia
| | - Matthew Gebert
- School of Physics and Astronomy, Monash University, Victoria, 3800, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria, 3800, Australia
| | - Julie Karel
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria, 3800, Australia
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria, 3800, Australia
| | - Mark T Edmonds
- School of Physics and Astronomy, Monash University, Victoria, 3800, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria, 3800, Australia
| | - Michael S Fuhrer
- School of Physics and Astronomy, Monash University, Victoria, 3800, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria, 3800, Australia
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49
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Sierra JF, Fabian J, Kawakami RK, Roche S, Valenzuela SO. Van der Waals heterostructures for spintronics and opto-spintronics. NATURE NANOTECHNOLOGY 2021; 16:856-868. [PMID: 34282312 DOI: 10.1038/s41565-021-00936-x] [Citation(s) in RCA: 116] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
The large variety of 2D materials and their co-integration in van der Waals heterostructures enable innovative device engineering. In addition, their atomically thin nature promotes the design of artificial materials by proximity effects that originate from short-range interactions. Such a designer approach is particularly compelling for spintronics, which typically harnesses functionalities from thin layers of magnetic and non-magnetic materials and the interfaces between them. Here we provide an overview of recent progress in 2D spintronics and opto-spintronics using van der Waals heterostructures. After an introduction to the forefront of spin transport research, we highlight the unique spin-related phenomena arising from spin-orbit and magnetic proximity effects. We further describe the ability to create multifunctional hybrid heterostructures based on van der Waals materials, combining spin, valley and excitonic degrees of freedom. We end with an outlook on perspectives and challenges for the design and production of ultracompact all-2D spin devices and their potential applications in conventional and quantum technologies.
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Affiliation(s)
- Juan F Sierra
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
| | - Jaroslav Fabian
- Institute for Theoretical Physics, University of Regensburg, Regensburg, Germany
| | | | - Stephan Roche
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Sergio O Valenzuela
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
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50
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Yang W, Cao Y, Han J, Lin X, Wang X, Wei G, Lv C, Bournel A, Zhao W. Spin-filter induced large magnetoresistance in 2D van der Waals magnetic tunnel junctions. NANOSCALE 2021; 13:862-868. [PMID: 33355579 DOI: 10.1039/d0nr07290g] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Two-dimensional (2D) van der Waals (vdW) heterostructures, known as layer-by-layer stacked 2D materials in a precisely chosen sequence, have received more and more attention in spintronics for their ultra-clean interface, unique electronic properties and 2D ferromagnetism. Motivated by the recent synthesis of monolayer 1T-VSe2 with ferromagnetic ordering and a high Curie temperature above room temperature, we investigate the bias-voltage driven spin transport properties of 2D magnetic tunnel junctions (MTJs) based on VSe2 utilizing density functional theory combined with the nonequilibrium Green's function method. In the device 1T-MoSe2/1T-VSe2/2H-WSe2/1T-VSe2/1T-MoSe2, the tunneling magneto-resistance (TMR) is incredibly satisfactory up to 5600%. Based on the analysis of evanescent states, this large TMR is attributed to the spin filter effect at the interface between 1T-VSe2 and 2H-WSe2, which overcomes the low spin polarization of 1T-VSe2. Furthermore, by inserting 2H-MoSe2, the spin filter effect is enhanced with decreasing current and the TMR is drastically improved to 1.7 × 105%. This work highlights the feasibility of 2D vdW heterostructures for ultra-low power spintronic applications by electronic structural engineering.
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Affiliation(s)
- Wei Yang
- Fert Beijing Research Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering & Beijing Advanced Innovation Center for Big Data and Brain Computing, Beihang University, Beijing 100191, China.
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