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Ying Z, Chen B, Li C, Wei B, Dai Z, Guo F, Pan D, Zhang H, Wu D, Wang X, Zhang S, Fei F, Song F. Large Exchange Bias Effect and Coverage-Dependent Interfacial Coupling in CrI 3/MnBi 2Te 4 van der Waals Heterostructures. Nano Lett 2023; 23:765-771. [PMID: 36542799 DOI: 10.1021/acs.nanolett.2c02882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Igniting interface magnetic ordering of magnetic topological insulators by building a van der Waals heterostructure can help to reveal novel quantum states and design functional devices. Here, we observe an interesting exchange bias effect, indicating successful interfacial magnetic coupling, in CrI3/MnBi2Te4 ferromagnetic insulator/antiferromagnetic topological insulator (FMI/AFM-TI) heterostructure devices. The devices originally exhibit a negative exchange bias field, which decays with increasing temperature and is unaffected by the back-gate voltage. When we change the device configuration to be half-covered by CrI3, the exchange bias becomes positive with a very large exchange bias field exceeding 300 mT. Such sensitive manipulation is explained by the competition between the FM and AFM coupling at the interface of CrI3 and MnBi2Te4, pointing to coverage-dependent interfacial magnetic interactions. Our work will facilitate the development of topological and antiferromagnetic devices.
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Affiliation(s)
- Zhe Ying
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing 210093, China
| | - Bo Chen
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing 210093, China
| | - Chunfeng Li
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing 210093, China
| | - Boyuan Wei
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing 210093, China
| | - Zheng Dai
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing 210093, China
| | - Fengyi Guo
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing 210093, China
| | - Danfeng Pan
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China
- Microfabrication and Integration Technology Center, Nanjing University, Nanjing 210093, China
| | - Haijun Zhang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing 210093, China
| | - Di Wu
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing 210093, China
| | - Xuefeng Wang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China
| | - Shuai Zhang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing 210093, China
- Atom Manufacturing Institute, Nanjing 211806, China
| | - Fucong Fei
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing 210093, China
- Atom Manufacturing Institute, Nanjing 211806, China
| | - Fengqi Song
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing 210093, China
- Atom Manufacturing Institute, Nanjing 211806, China
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Wu Y, Francisco B, Chen Z, Wang W, Zhang Y, Wan C, Han X, Chi H, Hou Y, Lodesani A, Yin G, Liu K, Cui YT, Wang KL, Moodera JS. A Van der Waals Interface Hosting Two Groups of Magnetic Skyrmions. Adv Mater 2022; 34:e2110583. [PMID: 35218078 DOI: 10.1002/adma.202110583] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Multiple magnetic skyrmion phases add an additional degree of freedom for skyrmion-based ultrahigh-density spin memory devices. Extending the field to 2D van der Waals magnets is a rewarding challenge, where the realizable degree of freedoms (e.g., thickness, twist angle, and electrical gating) and high skyrmion density result in intriguing new properties and enhanced functionality. In this work, a van der Waals interface, formed by two 2D ferromagnets Cr2 Ge2 Te6 and Fe3 GeTe2 with a Curie temperature of ≈65 and ≈205 K, respectively, hosting two groups of magnetic skyrmions, is reported. Two sets of topological Hall effect signals are observed below 6s0 K when Cr2 Ge2 Te6 is magnetically ordered. These two groups of skyrmions are directly imaged using magnetic force microscopy, and supported by micromagnetic simulations. Interestingly, the magnetic skyrmions persist in the heterostructure with zero applied magnetic field. The results are promising for the realization of skyrmionic devices based on van der Waals heterostructures hosting multiple skyrmion phases.
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Affiliation(s)
- Yingying Wu
- Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Brian Francisco
- Department of Physics and Astronomy, University of California, Riverside, CA, 92521, USA
| | - Zhijie Chen
- Department of Physics, Georgetown University, Washington, D.C., 20057, 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
| | - Yu Zhang
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Caihua Wan
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xiufeng Han
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Hang Chi
- Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- U.S. Army CCDC Army Research Laboratory, Adelphi, MD, 20783, USA
| | - Yasen Hou
- Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Alessandro Lodesani
- Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Gen Yin
- Department of Physics, Georgetown University, Washington, D.C., 20057, USA
| | - Kai Liu
- Department of Physics, Georgetown University, Washington, D.C., 20057, USA
| | - Yong-Tao Cui
- Department of Physics and Astronomy, University of California, Riverside, CA, 92521, USA
| | - Kang L Wang
- Department of Electrical and Computer Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Jagadeesh S Moodera
- Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Physics Department, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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Wu Y, Wang W, Pan L, Wang KL. Manipulating Exchange Bias in a Van der Waals Ferromagnet. Adv Mater 2022; 34:e2105266. [PMID: 34910836 DOI: 10.1002/adma.202105266] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Xi Y, Zhao M, Feng H, Sun Y, Man X, Xu X, Hao W, Dou S, Du Y. Epitaxial growth of bilayer Bi(110) on two-dimensional ferromagnetic Fe 3GeTe 2. J Phys Condens Matter 2021; 34:074003. [PMID: 34757949 DOI: 10.1088/1361-648x/ac386a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 11/10/2021] [Indexed: 06/13/2023]
Abstract
Heterostructures of two-dimensional (2D) layered materials with selective compositions play an important role in creating novel functionalities. Effective interface coupling between 2D ferromagnet and electronic materials would enable the generation of exotic physical phenomena caused by intrinsic symmetry breaking and proximity effect at interfaces. Here, epitaxial growth of bilayer Bi(110) on 2D ferromagnetic Fe3GeTe2(FGT) with large magnetic anisotropy has been reported. Bilayer Bi(110) islands are found to extend along fixed lattice directions of FGT. The six preferred orientations could be divided into two groups of three-fold symmetry axes with the difference approximately to 26°. Moreover, dI/dVmeasurements confirm the existence of interface coupling between bilayer Bi(110) and FGT. A variation of the energy gap at the edges of bilayer Bi(110) is also observed which is modulated by the interface coupling strengths associated with its buckled atomic structure. This system provides a good platform for further study of the exotic electronic properties of epitaxial Bi(110) on 2D ferromagnetic substrate and promotes potential applications in the field of spin devices.
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Affiliation(s)
- Yilian Xi
- School of Physics, Beihang University, Beijing 100191, People's Republic of China
- Institute for Superconducting and Electronic Materials (ISEM) and BUAA-UOW Joint Research Centre, Australian Institute for Innovative Materials (AIIM), University of Wollongong, Wollongong, NSW 2500, Australia
| | - Mengting Zhao
- School of Physics, Beihang University, Beijing 100191, People's Republic of China
- Institute for Superconducting and Electronic Materials (ISEM) and BUAA-UOW Joint Research Centre, Australian Institute for Innovative Materials (AIIM), University of Wollongong, Wollongong, NSW 2500, Australia
| | - Haifeng Feng
- School of Physics, Beihang University, Beijing 100191, People's Republic of China
| | - Ying Sun
- School of Physics, Beihang University, Beijing 100191, People's Republic of China
| | - Xingkun Man
- School of Physics, Beihang University, Beijing 100191, People's Republic of China
| | - Xun Xu
- Institute for Superconducting and Electronic Materials (ISEM) and BUAA-UOW Joint Research Centre, Australian Institute for Innovative Materials (AIIM), University of Wollongong, Wollongong, NSW 2500, Australia
| | - Weichang Hao
- School of Physics, Beihang University, Beijing 100191, People's Republic of China
| | - Shixue Dou
- Institute for Superconducting and Electronic Materials (ISEM) and BUAA-UOW Joint Research Centre, Australian Institute for Innovative Materials (AIIM), University of Wollongong, Wollongong, NSW 2500, Australia
| | - Yi Du
- School of Physics, Beihang University, Beijing 100191, People's Republic of China
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Zhang Z, Wu H, Sang L, Takahashi Y, Huang J, Wang L, Toda M, Akita IM, Koide Y, Koizumi S, Liao M. Enhancing Delta E Effect at High Temperatures of Galfenol/Ti/Single-Crystal Diamond Resonators for Magnetic Sensing. ACS Appl Mater Interfaces 2020; 12:23155-23164. [PMID: 32336083 DOI: 10.1021/acsami.0c06593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A conventional wisdom is that the sensing properties of magnetic sensors at high temperatures will be degraded due to the materials' deterioration. Here, the concept of high-temperature enhancing magnetic sensing is proposed based on the hybrid structure of SCD MEMS resonator functionalized with a high thermal-stable ferromagnetic galfenol (FeGa) film. The delta E effect of the magnetostrictive FeGa thin film on Ti/SCD cantilevers is investigated by varying the operating temperature from 300 to 773 K upon external magnetic fields. The multilayer structure magnetic sensor presents a high sensitivity of 71.1 Hz/mT and a low noise level of 10 nT/√Hz at 773 K for frequencies higher than 7.5 kHz. The high-temperature magnetic sensing performance exceeds those of the reported magnetic sensors. Furthermore, an anomalous behavior is observed on the delta E effect, which exhibits a positive temperature dependence with the law of Tn. Based on the resonance frequency shift of the FeGa/Ti/SCD cantilever, the strain coupling in the multilayers of the FeGa/Ti/SCD structure under a magnetic field is strengthened with increasing temperature. The delta E effect shows a strong relationship with the azimuthal angle, θ, as a sine function at 300 and 773 K. This work provides a strategy to develop magnetic sensors for high-temperature applications with performance superior to that of the present ones.
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Affiliation(s)
- Zilong Zhang
- National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, People's Republic of China
| | - Haihua Wu
- National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - Liwen Sang
- National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - Yukiko Takahashi
- National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - Jian Huang
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, People's Republic of China
| | - Linjun Wang
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, People's Republic of China
| | - Masaya Toda
- Graduate School of Engineering, Tohoku University, Sendai, Miyagi 9808579, Japan
| | | | - Yasuo Koide
- National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - Satoshi Koizumi
- National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - Meiyong Liao
- National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
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Liao F, Deng J, Chen X, Wang Y, Zhang X, Liu J, Zhu H, Chen L, Sun Q, Hu W, Wang J, Zhou J, Zhou P, Zhang DW, Wan J, Bao W. A Dual-Gate MoS 2 Photodetector Based on Interface Coupling Effect. Small 2020; 16:e1904369. [PMID: 31769618 DOI: 10.1002/smll.201904369] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/25/2019] [Indexed: 06/10/2023]
Abstract
2D transition metal dichalcogenides (TMDs) based photodetectors have shown great potential for the next generation optoelectronics. However, most of the reported MoS2 photodetectors function under the photogating effect originated from the charge-trap mechanism, which is difficult for quantitative control. Such devices generally suffer from a poor compromise between response speed and responsivity (R) and large dark current. Here, a dual-gated (DG) MoS2 phototransistor operating based on the interface coupling effect (ICE) is demonstrated. By simultaneously applying a negative top-gate voltage (VTG ) and positive back-gate voltage (VBG ) to the MoS2 channel, the photogenerated holes can be effectively trapped in the depleted region under TG. An ultrahigh R of ≈105 A W-1 and detectivity (D*) of ≈1014 Jones are achieved in several devices with different thickness under Pin of 53 µW cm-2 at VTG = -5 V. Moreover, the response time of the DG phototransistor can also be modulated based on the ICE. Based on these systematic measurements of MoS2 DG phototransistors, the results show that the ICE plays an important role in the modulation of photoelectric performances. The results also pave the way for the future optoelectrical application of 2D TMDs materials and prompt for further investigation in the DG structured phototransistors.
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Affiliation(s)
- Fuyou Liao
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433, China
| | - Jianan Deng
- State Key Laboratory of ASIC and System, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Xinyu Chen
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433, China
| | - Yin Wang
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433, China
| | - Xinzhi Zhang
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433, China
| | - Jian Liu
- State Key Laboratory of ASIC and System, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Hao Zhu
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433, China
| | - Lin Chen
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433, China
| | - Qingqing Sun
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433, China
| | - Weida Hu
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
| | - Jianlu Wang
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
| | - Jing Zhou
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
| | - Peng Zhou
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433, China
| | - David Wei Zhang
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433, China
| | - Jing Wan
- State Key Laboratory of ASIC and System, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Wenzhong Bao
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433, China
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Li Y, Zhang L, Zhang Q, Li C, Yang T, Deng Y, Gu L, Wu D. Emergent Topological Hall Effect in La 0.7Sr 0.3MnO 3/SrIrO 3 Heterostructures. ACS Appl Mater Interfaces 2019; 11:21268-21274. [PMID: 31117466 DOI: 10.1021/acsami.9b05562] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Recently, perovskite oxide heterostructures have drawn great attention because multiple and complex coupling at the heterointerface may produce novel magnetic and electric phenomena that are not expected in homogeneous materials either in the bulk or in films. In this work, we report for the first time that an emergent giant topological Hall effect (THE), associated with a noncoplanar (NC) spin texture, can be induced in ferromagnetic (FM) La0.7Sr0.3MnO3 thin films in a wide temperature range of up to 200 K by constructing La0.7Sr0.3MnO3/SrIrO3 epitaxial heterostructures on (001) SrTiO3 substrates. This THE is not observed in La0.7Sr0.3MnO3 single-layer films or La0.7Sr0.3MnO3/SrTiO3/SrIrO3 trilayer heterostructures, indicating the relevance of the La0.7Sr0.3MnO3/SrIrO3 interface, where the Dzyaloshinskii-Moriya interaction due to strong spin-orbital coupling in SrIrO3 may play a crucial role. The fictitious field associated with THE is independent of temperature in La0.7Sr0.3MnO3/SrIrO3 heterostructures, suggesting that the NC spin texture may be magnetic skyrmions. This work demonstrates the feasibility of using SrIrO3 to generate novel magnetic and transport characteristics by interfacing with other correlated oxides, which might be useful to novel spintronic applications.
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Affiliation(s)
| | - Lunyong Zhang
- Max Plank POSTECH Center for Complex Phase Materials , Max Planck POSTECH/Korea Research Initiative , Pohang 790-784 , Korea
- Max Planck Institute for Chemical Physics of Solids , Dresden 01187 , Germany
| | - Qinghua Zhang
- 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 100190 , China
| | | | - Tieying Yang
- Shanghai Institute of Applied Physics , Chinese Academy of Sciences , Shanghai 201800 , China
| | | | - Lin Gu
- 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 100190 , China
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Molinari A, Hahn H, Kruk R. Voltage-Control of Magnetism in All-Solid-State and Solid/Liquid Magnetoelectric Composites. Adv Mater 2019; 31:e1806662. [PMID: 30785649 DOI: 10.1002/adma.201806662] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 12/20/2018] [Indexed: 06/09/2023]
Abstract
The control of magnetism by means of low-power electric fields, rather than dissipative flowing currents, has the potential to revolutionize conventional methods of data storage and processing, sensing, and actuation. A promising strategy relies on the utilization of magnetoelectric composites to finely tune the interplay between electric and magnetic degrees of freedom at the interface of two functional materials. Albeit early works predominantly focused on the magnetoelectric coupling at solid/solid interfaces; however, recently there has been an increased interest related to the opportunities offered by liquid-gating techniques. Here, a comparative overview on voltage control of magnetism in all-solid-state and solid/liquid composites is presented within the context of the principal coupling mediators, i.e., strain, charge carrier doping, and ionic intercalation. Further, an exhaustive and critical discussion is carried out, concerning the suitability of using the common definition of coupling coefficient α C = Δ M Δ E to compare the strength of the interaction between electricity and magnetism among different magnetoelectric systems.
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Affiliation(s)
- Alan Molinari
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Horst Hahn
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
- KIT-TUD-Joint Research Laboratory Nanomaterials, Technical University Darmstadt, Jovanka-Bontschits-Strasse 2, 64287, Darmstadt, Germany
| | - Robert Kruk
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
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Zhang S, Guo X, Tang Y, Ma D, Zhu Y, Wang Y, Li S, Han M, Chen D, Ma J, Wu B, Ma X. Polarization Rotation in Ultrathin Ferroelectrics Tailored by Interfacial Oxygen Octahedral Coupling. ACS Nano 2018; 12:3681-3688. [PMID: 29630820 DOI: 10.1021/acsnano.8b00862] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Multiple polar states and giant piezoelectric responses could be driven by polarization rotation in ferroelectric films, which have potential functionalities in modern material applications. Although theoretical calculations have predicted polarization rotation in pure PbTiO3 films without domain walls and strains, direct experiment has rarely confirmed such polar states under this condition. Here, we observed that interfacial oxygen octahedral coupling (OOC) can introduce an oxygen octahedral rotation, which induces polarization rotation in single domain PbTiO3 films with negligible strains. We have grown ultrathin PbTiO3 films (3.2 nm) on both SrTiO3 and Nb:SrTiO3 substrates and applied aberration-corrected scanning transmission electron microscopy (STEM) to study the interfacial OOC effect. Atomic mappings unit cell by unit cell demonstrate that polarization rotation occurs in PbTiO3 films on both substrates. The distortion of oxygen octahedra in PbTiO3 is proven by annular bright-field STEM. The critical thickness for this polarization rotation is about 4 nm (10 unit cells), above which polarization rotation disappears. First-principles calculations manifest that the interfacial OOC is responsible for the polarization rotation state. These results may shed light on further understanding the polarization behavior in ultrathin ferroelectrics and be helpful to develop relevant devices as polarization rotation is known to be closely related to superior electromechanical responses.
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Affiliation(s)
- Sirui Zhang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Wenhua Road 72 , Shenyang 110016 , China
- University of Chinese Academy of Sciences , Yuquan Road 19 , Beijing 100049 , China
| | - Xiangwei Guo
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Wenhua Road 72 , Shenyang 110016 , China
- School of Materials Science and Engineering , University of Science and Technology of China , Hefei 230026 , China
| | - Yunlong Tang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Wenhua Road 72 , Shenyang 110016 , China
| | - Desheng Ma
- School of Physics , Nankai University , Weijin Road 94 , Tianjin 300071 , China
| | - Yinlian Zhu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Wenhua Road 72 , Shenyang 110016 , China
| | - Yujia Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Wenhua Road 72 , Shenyang 110016 , China
| | - Shuang Li
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Wenhua Road 72 , Shenyang 110016 , China
- University of Chinese Academy of Sciences , Yuquan Road 19 , Beijing 100049 , China
| | - Mengjiao Han
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Wenhua Road 72 , Shenyang 110016 , China
- University of Chinese Academy of Sciences , Yuquan Road 19 , Beijing 100049 , China
| | - Dong Chen
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Wenhua Road 72 , Shenyang 110016 , China
| | - Jinyuan Ma
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Wenhua Road 72 , Shenyang 110016 , China
- University of Chinese Academy of Sciences , Yuquan Road 19 , Beijing 100049 , China
- School of Materials Science and Engineering , Lanzhou University of Technology , Langongping Road 287 , Lanzhou 730050 , China
| | - Bo Wu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Wenhua Road 72 , Shenyang 110016 , China
- School of Materials Science and Engineering , University of Science and Technology of China , Hefei 230026 , China
| | - Xiuliang Ma
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Wenhua Road 72 , Shenyang 110016 , China
- School of Materials Science and Engineering , Lanzhou University of Technology , Langongping Road 287 , Lanzhou 730050 , China
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Wu JB, Hu ZX, Zhang X, Han WP, Lu Y, Shi W, Qiao XF, Ijiäs M, Milana S, Ji W, Ferrari AC, Tan PH. Interface Coupling in Twisted Multilayer Graphene by Resonant Raman Spectroscopy of Layer Breathing Modes. ACS Nano 2015; 9:7440-7449. [PMID: 26062640 DOI: 10.1021/acsnano.5b02502] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Raman spectroscopy is the prime nondestructive characterization tool for graphene and related layered materials. The shear (C) and layer breathing modes (LBMs) are due to relative motions of the planes, either perpendicular or parallel to their normal. This allows one to directly probe the interlayer interactions in multilayer samples. Graphene and other two-dimensional (2d) crystals can be combined to form various hybrids and heterostructures, creating materials on demand with properties determined by the interlayer interaction. This is the case even for a single material, where multilayer stacks with different relative orientations have different optical and electronic properties. In twisted multilayer graphene there is a significant enhancement of the C modes due to resonance with new optically allowed electronic transitions, determined by the relative orientation of the layers. Here we show that this applies also to the LBMs, which can be now directly measured at room temperature. We find that twisting has a small effect on LBMs, quite different from the case of the C modes. This implies that the periodicity mismatch between two twisted layers mostly affects shear interactions. Our work shows that ultralow-frequency Raman spectroscopy is an ideal tool to uncover the interface coupling of 2d hybrids and heterostructures.
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Affiliation(s)
- Jiang-Bin Wu
- †State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Zhi-Xin Hu
- ‡Department of Physics, Renmin University of China, Beijing 100872, China
| | - Xin Zhang
- †State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Wen-Peng Han
- †State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Yan Lu
- †State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Wei Shi
- †State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Xiao-Fen Qiao
- †State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Mari Ijiäs
- §Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, U.K
| | - Silvia Milana
- §Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, U.K
| | - Wei Ji
- ‡Department of Physics, Renmin University of China, Beijing 100872, China
| | - Andrea C Ferrari
- §Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, U.K
| | - Ping-Heng Tan
- †State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
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