1
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Liu Q, Nanthakumar S, Li B, Cheng T, Bittner F, Ma C, Ding F, Zheng L, Roth B, Zhuang X. Converse Flexoelectricity in van der Waals (vdW) Three-Dimensional Topological Insulator Nanoflakes. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2024; 128:16265-16273. [PMID: 39355009 PMCID: PMC11440597 DOI: 10.1021/acs.jpcc.4c05690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2024] [Revised: 09/01/2024] [Accepted: 09/03/2024] [Indexed: 10/03/2024]
Abstract
Low-dimensional van der Waals (vdW) three-dimensional (3D) topological insulators (TIs) have been overlooked, regarding their electromechanical properties. In this study, we experimentally investigate the electromechanical coupling of low-dimensional 3D TIs with a centrosymmetric crystal structure, where a binary compound, bismuth selenide (Bi2Se3), is taken as an example. Piezoresponse force microscopy (PFM) results of Bi2Se3 nanoflakes show that the material exhibits both out-of-plane and in-plane electromechanical responses. With careful analyses, the electromechanical responses are verified to arise from the converse flexoelectricity. The Bi2Se3 nanoflakes have a decreasing effective out-of-plane piezoelectric coefficient d 33 eff with the thickness increasing, with the d 33 eff value of ∼0.65 pm V-1 for the 37 nm-thick sample. The measured effective out-of-plane piezoelectric coefficient is mainly contributed by the flexoelectric coefficient, μ39, which is estimated to be approximately 0.13 nC m-1. The results can help to understand the flexoelectricity of low-dimensional vdW TIs with centrosymmetric crystal structures, which is crucial for the design of nanoelectromechanical devices and spintronics built by vdW TIs.
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Affiliation(s)
- Qiong Liu
- Faculty
of Mathematics and Physics, Leibniz University
Hannover, Hannover 30167, Germany
| | | | - Bin Li
- Faculty
of Mathematics and Physics, Leibniz University
Hannover, Hannover 30167, Germany
| | - Teresa Cheng
- Faculty
of Mathematics and Physics, Leibniz University
Hannover, Hannover 30167, Germany
| | - Florian Bittner
- Institute
of Plastics and Circular Economy (IKK), Faculty of Mechanical Engineering, Leibniz University Hannover, Hannover 30823, Germany
| | - Chenxi Ma
- Institute
of Solid State Physics, Faculty of Mathematics and Physics, Leibniz University Hannover, Hannover 30167, Germany
| | - Fei Ding
- Institute
of Solid State Physics, Faculty of Mathematics and Physics, Leibniz University Hannover, Hannover 30167, Germany
| | - Lei Zheng
- Hannover
Centre for Optical Technologies, Leibniz
University Hannover, Hannover 30167, Germany
| | - Bernhard Roth
- Hannover
Centre for Optical Technologies, Leibniz
University Hannover, Hannover 30167, Germany
- Cluster
of Excellence PhoenixD (Photonics, Optics and Engineering −
Innovation Across Disciplines), Hannover 30167, Germany
| | - Xiaoying Zhuang
- Faculty
of Mathematics and Physics, Leibniz University
Hannover, Hannover 30167, Germany
- Department
of Geotechnical Engineering, College of Civil Engineering, Tongji University, Shanghai 200092, China
- Cluster
of Excellence PhoenixD (Photonics, Optics and Engineering −
Innovation Across Disciplines), Hannover 30167, Germany
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2
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Shi H, Zhang J, Xi Y, Li H, Chen J, Ahmed I, Ma Z, Cheng N, Zhou X, Jin H, Zhou X, Liu J, Sun Y, Wang J, Li J, Yu T, Hao W, Zhang S, Du Y. Dynamic Behavior of Above-Room-Temperature Robust Skyrmions in 2D Van der Waals Magnet. NANO LETTERS 2024; 24:11246-11254. [PMID: 39207036 DOI: 10.1021/acs.nanolett.4c02835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Magnetic skyrmions are swirl-like spin configurations that present topological properties, which have great potential as information carriers for future high-density and low-energy-consumption devices. The optimization of skyrmion-hosting materials that can be integrated with semiconductor-based circuits is the primary challenge for their industrialization. Two-dimensional van der Waals ferromagnets are emerging materials that have excellent carrier mobility and compatibility with integrated circuits, making them an ideal candidate for spintronic devices. Here, we report the realization of skyrmions at above room temperature in the 2D ferromagnet Fe3GaTe2. The thickness tunability of their skyrmion size and the formation of the skyrmion lattice are revealed. Furthermore, we demonstrate that the skyrmions can be moved by a low-density current at room temperature, together with an apparent skyrmion Hall effect, which is consistent with our quantitative micromagnetic simulation. Our work offers a promising 2D material platform for harnessing magnetic skyrmions in practical device applications.
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Affiliation(s)
- Hanqing Shi
- School of Physics, Beihang University, Haidian District, Beijing 100191, China
| | - Jingwei Zhang
- School of Physics, Beihang University, Haidian District, Beijing 100191, China
| | | | - Heping Li
- School of Physics, Beihang University, Haidian District, Beijing 100191, China
| | - Jingyi Chen
- School of Physical Science and Technology, Shanghai Tech University, Pudong New Area, Shanghai 201210, China
| | - Iftikhar Ahmed
- School of Physical and Technology, Wuhan University, Wuhan, Hubei 430072, China
| | - Zhijie Ma
- School of Physics, Beihang University, Haidian District, Beijing 100191, China
| | - Ningyan Cheng
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Xiang Zhou
- School of Physical Science and Technology, Shanghai Tech University, Pudong New Area, Shanghai 201210, China
| | - Haonan Jin
- School of Physical Science and Technology, Shanghai Tech University, Pudong New Area, Shanghai 201210, China
| | - Xinyi Zhou
- School of Physical and Technology, Wuhan University, Wuhan, Hubei 430072, China
| | - Jiaqi Liu
- School of Physics, Beihang University, Haidian District, Beijing 100191, China
| | - Ying Sun
- School of Physics, Beihang University, Haidian District, Beijing 100191, China
| | - Jianfeng Wang
- School of Physics, Beihang University, Haidian District, Beijing 100191, China
| | - Jun Li
- School of Physical Science and Technology, Shanghai Tech University, Pudong New Area, Shanghai 201210, China
| | - Ting Yu
- School of Physical and Technology, Wuhan University, Wuhan, Hubei 430072, China
- Wuhan Institute of Quantum Technology, Wuhan 430206, China
- Key Laboratory of Artificial Micro- and Nano- structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Weichang Hao
- School of Physics, Beihang University, Haidian District, Beijing 100191, China
| | - Shilei Zhang
- School of Physical Science and Technology, Shanghai Tech University, Pudong New Area, Shanghai 201210, China
| | - Yi Du
- School of Physics, Beihang University, Haidian District, Beijing 100191, China
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3
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Garanin DA, Soriano JF, Chudnovsky EM. Melting and freezing of a skyrmion lattice. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:475802. [PMID: 39142350 DOI: 10.1088/1361-648x/ad6f8b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2024] [Accepted: 08/14/2024] [Indexed: 08/16/2024]
Abstract
We report comprehensive Monte-Carlo studies of the melting of skyrmion lattices (SkL) in systems of small, medium, and large sizes with the number of skyrmions ranging from 103to over 105. Large systems exhibit hysteresis similar to that observed in real experiments on the melting of SkLs. For sufficiently small systems which achieve thermal equilibrium, a fully reversible sharp solid-liquid transition on temperature with no intermediate hexatic phase is observed. A similar behavior is found on changing the magnetic field that provides the control of pressure in the SkL. We find that on heating the melting transition occurs via a formation of grains with different orientations of hexagonal axes. On cooling, the fluctuating grains coalesce into larger clusters until a uniform orientation of hexagonal axes is slowly established. The observed scenario is caused by collective effects involving defects and is more complex than a simple picture of a transition driven by the unbinding and annihilation of dislocation and disclination pairs.
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Affiliation(s)
- Dmitry A Garanin
- Physics Department, Herbert H. Lehman College and Graduate School, The City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468-1589, United States of America
| | - Jorge F Soriano
- Physics Department, Herbert H. Lehman College and Graduate School, The City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468-1589, United States of America
| | - Eugene M Chudnovsky
- Physics Department, Herbert H. Lehman College and Graduate School, The City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468-1589, United States of America
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4
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Birch MT, Yasin FS, Litzius K, Powalla L, Wintz S, Schulz F, Kossak AE, Weigand M, Scholz T, Lotsch BV, Schütz G, Yu XZ, Burghard M. Influence of Magnetic Sublattice Ordering on Skyrmion Bubble Stability in 2D Magnet Fe 5GeTe 2. ACS NANO 2024; 18:18246-18256. [PMID: 38975730 PMCID: PMC11256745 DOI: 10.1021/acsnano.4c00853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 07/09/2024]
Abstract
The realization of above room-temperature ferromagnetism in the two-dimensional (2D) magnet Fe5GeTe2 represents a major advance for the use of van der Waals (vdW) materials in practical spintronic applications. In particular, observations of magnetic skyrmions and related states within exfoliated flakes of this material provide a pathway to the fine-tuning of topological spin textures via 2D material heterostructure engineering. However, there are conflicting reports as to the nature of the magnetic structures in Fe5GeTe2. The matter is further complicated by the study of two types of Fe5GeTe2 crystals with markedly different structural and magnetic properties, distinguished by their specific fabrication procedure: whether they are slowly cooled or rapidly quenched from the growth temperature. In this work, we combine X-ray and electron microscopy to observe the formation of magnetic stripe domains, skyrmion-like type-I, and topologically trivial type-II bubbles, within exfoliated flakes of Fe5GeTe2. The results reveal the influence of the magnetic ordering of the Fe1 sublattice below 150 K, which dramatically alters the magnetocrystalline anisotropy and leads to a complex magnetic phase diagram and a sudden change of the stability of the magnetic textures. In addition, we highlight the significant differences in the magnetic structures intrinsic to slow-cooled and quenched Fe5GeTe2 flakes.
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Affiliation(s)
- Max T. Birch
- Max
Planck Institute for Intelligent Systems, Heisenbergstraße 3, Stuttgart 70569, Germany
- RIKEN
Center for Emergent Matter Science, Hirosawa 2-1, Wako 351-0198, Japan
| | - Fehmi S. Yasin
- RIKEN
Center for Emergent Matter Science, Hirosawa 2-1, Wako 351-0198, Japan
- Center
for Nanophase Materials Sciences, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Kai Litzius
- Max
Planck Institute for Intelligent Systems, Heisenbergstraße 3, Stuttgart 70569, Germany
| | - Lukas Powalla
- Max
Planck Institute for Solid State Research, Heisenbergstraße 1, Stuttgart 70569, Germany
| | - Sebastian Wintz
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, Berlin 14109, Germany
| | - Frank Schulz
- Max
Planck Institute for Intelligent Systems, Heisenbergstraße 3, Stuttgart 70569, Germany
| | - Alexander E. Kossak
- Department
of Materials Science and Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Markus Weigand
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, Berlin 14109, Germany
| | - Tanja Scholz
- Max
Planck Institute for Solid State Research, Heisenbergstraße 1, Stuttgart 70569, Germany
| | - Bettina V. Lotsch
- Max
Planck Institute for Solid State Research, Heisenbergstraße 1, Stuttgart 70569, Germany
- University
of Munich (LMU), Butenandtstraße
5-13 (Haus D), München 81377, Germany
| | - Gisela Schütz
- Max
Planck Institute for Intelligent Systems, Heisenbergstraße 3, Stuttgart 70569, Germany
| | - Xiuzhen Z. Yu
- RIKEN
Center for Emergent Matter Science, Hirosawa 2-1, Wako 351-0198, Japan
| | - Marko Burghard
- Max
Planck Institute for Solid State Research, Heisenbergstraße 1, Stuttgart 70569, Germany
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5
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Zhu R, Zheng S, Li X, Wang T, Tan C, Yu T, Liu Z, Wang X, Li J, Wang J, Gao P. Atomic-Scale Tracking Topological Phase Transition Dynamics of Polar Vortex-Antivortex Pairs. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2312072. [PMID: 38734889 DOI: 10.1002/adma.202312072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 04/02/2024] [Indexed: 05/13/2024]
Abstract
Non-trivial topological structures, such as vortex-antivortex (V-AV) pairs, have garnered significant attention in the field of condensed matter physics. However, the detailed topological phase transition dynamics of V-AV pairs, encompassing behaviors like self-annihilation, motion, and dissociation, have remained elusive in real space. Here, polar V-AV pairs are employed as a model system, and their transition pathways are tracked with atomic-scale resolution, facilitated by in situ (scanning) transmission electron microscopy and phase field simulations. This investigation reveals that polar vortices and antivortices can stably coexist as bound pairs at room temperature, and their polarization decreases with heating. No dissociation behavior is observed between the V-AV phase at room temperature and the paraelectric phase at high temperature. However, the application of electric fields can promote the approach of vortex and antivortex cores, ultimately leading to their annihilation near the interface. Revealing the transition process mediated by polar V-AV pairs at the atomic scale, particularly the role of polar antivortex, provides new insights into understanding the topological phases of matter and their topological phase transitions. Moreover, the detailed exploration of the dynamics of polar V-AV pairs under thermal and electrical fields lays a solid foundation for their potential applications in electronic devices.
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Affiliation(s)
- Ruixue Zhu
- Electron Microscopy Laboratory, and International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Sizheng Zheng
- Department of Engineering Mechanics, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Xiaomei Li
- Electron Microscopy Laboratory, and International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- School of Integrated Circuits, East China Normal University, Shanghai, 200241, China
| | - Tao Wang
- Electron Microscopy Laboratory, and International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Congbing Tan
- Hunan Provincial Key Laboratory of Intelligent Sensors and Advanced Sensor Materials, School of Physics and Electronics, Hunan University of Science and Technology, Xiangtan, Hunan, 411201, China
| | - Tiancheng Yu
- Electron Microscopy Laboratory, and International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Zhetong Liu
- Electron Microscopy Laboratory, and International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Xinqiang Wang
- State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, China
- Collaborative Innovation Centre of Quantum Matter, Beijing, 100871, China
| | - Jiangyu Li
- Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Jie Wang
- Department of Engineering Mechanics, Zhejiang University, Hangzhou, Zhejiang, 310027, China
- Zhejiang Laboratory, Hangzhou, 311100, China
| | - Peng Gao
- Electron Microscopy Laboratory, and International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Collaborative Innovation Centre of Quantum Matter, Beijing, 100871, China
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6
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Skaggs C, Siegfried PE, Cho JS, Xin Y, Garlea VO, Taddei KM, Bhandari H, Croft M, Ghimire NJ, Jang JI, Tan X. Ba 4RuMn 2O 10: A Noncentrosymmetric Polar Crystal Structure with Disordered Trimers. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2024; 36:6053-6061. [PMID: 38947978 PMCID: PMC11210430 DOI: 10.1021/acs.chemmater.4c00586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 05/06/2024] [Accepted: 05/22/2024] [Indexed: 07/02/2024]
Abstract
Phase-pure polycrystalline Ba4RuMn2O10 was prepared and determined to adopt the noncentrosymmetric polar crystal structure (space group Cmc21) based on results of second harmonic generation, convergent beam electron diffraction, and Rietveld refinements using powder neutron diffraction data. The crystal structure features zigzag chains of corner-shared trimers, which contain three distorted face-sharing octahedra. The three metal sites in the trimers are occupied by disordered Ru/Mn with three different ratios: Ru1:Mn1 = 0.202(8):0.798(8), Ru2:Mn2 = 0.27(1):0.73(1), and Ru3:Mn3 = 0.40(1):0.60(1), successfully lowering the symmetry and inducing the polar crystal structure from the centrosymmetric parent compounds Ba4T3O10 (T = Mn, Ru; space group Cmca). The valence state of Ru/Mn is confirmed to be +4 according to X-ray absorption near-edge spectroscopy. Ba4RuMn2O10 is a narrow bandgap (∼0.6 eV) semiconductor exhibiting spin-glass behavior with strong magnetic frustration and antiferromagnetic interactions.
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Affiliation(s)
- Callista
M. Skaggs
- Department
of Chemistry and Biochemistry, George Mason
University, Fairfax, Virginia 22030, United States
| | - Peter E. Siegfried
- Department
of Physics and Astronomy, George Mason University, Fairfax, Virginia 22030, United States
- Quantum
Science and Engineering Center, George Mason
University, Fairfax, Virginia 22030, United States
| | - Jun Sang Cho
- Department
of Physics, Sogang University, Seoul 04017, Republic of Korea
| | - Yan Xin
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
| | - V. Ovidiu Garlea
- Neutron Scattering
Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Keith M. Taddei
- Neutron Scattering
Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- X-ray
Science
Division, Advanced Photon Source, Argonne
National Laboratory, Lemont, Illinois 60439, United States
| | - Hari Bhandari
- Department
of Physics and Astronomy, George Mason University, Fairfax, Virginia 22030, United States
- Department
of Physics and Astronomy and Stavropoulos Center for Complex Quantum
Matter, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Mark Croft
- Department
of Physics and Astronomy, Rutgers, The State
University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Nirmal J. Ghimire
- Department
of Physics and Astronomy and Stavropoulos Center for Complex Quantum
Matter, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Joon I. Jang
- Department
of Physics, Sogang University, Seoul 04017, Republic of Korea
| | - Xiaoyan Tan
- Department
of Chemistry and Biochemistry, George Mason
University, Fairfax, Virginia 22030, United States
- Quantum
Science and Engineering Center, George Mason
University, Fairfax, Virginia 22030, United States
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7
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Averyanov DV, Sokolov IS, Taldenkov AN, Parfenov OE, Larionov KV, Sorokin PB, Kondratev OA, Tokmachev AM, Storchak VG. Engineering of a Layered Ferromagnet via Graphitization: An Overlooked Polymorph of GdAlSi. J Am Chem Soc 2024; 146:15761-15770. [PMID: 38825888 DOI: 10.1021/jacs.4c01472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Layered magnets are stand-out materials because of their range of functional properties that can be controlled by external stimuli. Regretfully, the class of such compounds is rather narrow, prompting the search for new members. Graphitization─stabilization of layered graphitic structures in the 2D limit─is being discussed for cubic materials. We suggest the phenomenon to extend beyond cubic structures; it can be employed as a viable route to a variety of layered materials. Here, the idea of graphitization is put into practice to produce a new layered magnet, GdAlSi. The honeycomb material, based on graphene-like layers AlSi, is studied both experimentally and theoretically. Epitaxial films of GdAlSi are synthesized on silicon; the critical thickness for the stability of the layered polymorph is around 20 monolayers. Notably, the layered polymorph of GdAlSi demonstrates ferromagnetism, in contrast to the nonlayered, tetragonal polymorph. The ferromagnetism is further supported by electron transport measurements revealing negative magnetoresistance and the anomalous Hall effect. The results show that graphitization can be a powerful tool in the design of functional layered materials.
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Affiliation(s)
- Dmitry V Averyanov
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, 123182 Moscow, Russia
| | - Ivan S Sokolov
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, 123182 Moscow, Russia
| | - Alexander N Taldenkov
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, 123182 Moscow, Russia
| | - Oleg E Parfenov
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, 123182 Moscow, Russia
| | - Konstantin V Larionov
- Laboratory of Digital Materials Science, National University of Science and Technology MISIS, Leninskiy prospect 4, 119049 Moscow, Russia
| | - Pavel B Sorokin
- Laboratory of Digital Materials Science, National University of Science and Technology MISIS, Leninskiy prospect 4, 119049 Moscow, Russia
| | - Oleg A Kondratev
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, 123182 Moscow, Russia
| | - Andrey M Tokmachev
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, 123182 Moscow, Russia
| | - Vyacheslav G Storchak
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, 123182 Moscow, Russia
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8
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Jami P, Chaudhuri P, Dasgupta C, Ghosal A. Effect of disorder on phases across two-dimensional thermal melting. Phys Rev E 2024; 109:L062101. [PMID: 39021015 DOI: 10.1103/physreve.109.l062101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 04/11/2024] [Indexed: 07/20/2024]
Abstract
We study melting in a two-dimensional system of classical particles with Gaussian-core interactions in disordered environments. The pure system validates the conventional two-step melting with a hexatic phase intervening between the solid and the liquid. This picture is modified in the presence of pinning impurities. A random distribution of pinning centers forces a hexaticlike low-temperature phase that transits into a liquid at a single melting temperature T_{m}^{RP}. In contrast, pinning centers located at randomly chosen sites of a perfect crystal anchor a solid at low temperatures which undergoes a direct transition to the liquid at T_{m}^{CP}. Thus, the two-step melting is lost in either case of disorder. We discuss the characteristics of melting depending on the nature of the impurities.
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9
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Denneulin T, Kovács A, Boltje R, Kiselev NS, Dunin-Borkowski RE. Geometric phase analysis of magnetic skyrmion lattices in Lorentz transmission electron microscopy images. Sci Rep 2024; 14:12286. [PMID: 38811716 DOI: 10.1038/s41598-024-62873-8] [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: 02/12/2024] [Accepted: 05/22/2024] [Indexed: 05/31/2024] Open
Abstract
Magnetic skyrmions are quasi-particles with a swirling spin texture that form two-dimensional lattices. Skyrmion lattices can exhibit defects in response to geometric constraints, variations of temperature or applied magnetic fields. Measuring deformations in skyrmion lattices is important to understand the interplay between the lattice structure and external influences. Geometric phase analysis (GPA) is a Fourier-based image processing method that is used to measure deformation fields in high resolution transmission electron microscopy (TEM) images of crystalline materials. Here, we show that GPA can be applied quantitatively to Lorentz TEM images of two-dimensional skyrmion lattices obtained from a chiral magnet of FeGe. First, GPA is used to map deformation fields around a 5-7 dislocation and the results are compared with the linear theory of elasticity. Second, rotation angles between skyrmion crystal grains are measured and compared with angles calculated from the density of dislocations. Third, an orientational order parameter and the corresponding correlation function are calculated to describe the evolution of the disorder as a function of applied magnetic field. The influence of sources of artifacts such as geometric distortions and large defoci are also discussed.
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Affiliation(s)
- Thibaud Denneulin
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, 52425, Jülich, Germany.
| | - András Kovács
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Raluca Boltje
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Nikolai S Kiselev
- Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425, Jülich, Germany
| | - Rafal E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, 52425, Jülich, Germany
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10
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Zhang C, Jiang Z, Jiang J, He W, Zhang J, Hu F, Zhao S, Yang D, Liu Y, Peng Y, Yang H, Yang H. Above-room-temperature chiral skyrmion lattice and Dzyaloshinskii-Moriya interaction in a van der Waals ferromagnet Fe 3-xGaTe 2. Nat Commun 2024; 15:4472. [PMID: 38796498 PMCID: PMC11127993 DOI: 10.1038/s41467-024-48799-9] [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: 09/23/2023] [Accepted: 05/14/2024] [Indexed: 05/28/2024] Open
Abstract
Skyrmions in existing 2D van der Waals (vdW) materials have primarily been limited to cryogenic temperatures, and the underlying physical mechanism of the Dzyaloshinskii-Moriya interaction (DMI), a crucial ingredient for stabilizing chiral skyrmions, remains inadequately explored. Here, we report the observation of Néel-type skyrmions in a vdW ferromagnet Fe3-xGaTe2 above room temperature. Contrary to previous assumptions of centrosymmetry in Fe3-xGaTe2, the atomic-resolution scanning transmission electron microscopy reveals that the off-centered FeΙΙ atoms break the spatial inversion symmetry, rendering it a polar metal. First-principles calculations further elucidate that the DMI primarily stems from the Te sublayers through the Fert-Lévy mechanism. Remarkably, the chiral skyrmion lattice in Fe3-xGaTe2 can persist up to 330 K at zero magnetic field, demonstrating superior thermal stability compared to other known skyrmion vdW magnets. This work provides valuable insights into skyrmionics and presents promising prospects for 2D material-based skyrmion devices operating beyond room temperature.
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Affiliation(s)
- Chenhui Zhang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Ze Jiang
- School of Materials and Energy and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, China
| | - Jiawei Jiang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Wa He
- School of Materials and Energy and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, China
| | - Junwei Zhang
- School of Materials and Energy and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, China
| | - Fanrui Hu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Shishun Zhao
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Dongsheng Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Yakun Liu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Yong Peng
- School of Materials and Energy and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, China.
| | - Hongxin Yang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
- Center for Quantum Matter, School of Physics, Zhejiang University, Hangzhou, 310058, China.
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore.
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11
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Zhang H, Shao YT, Chen X, Zhang B, Wang T, Meng F, Xu K, Meisenheimer P, Chen X, Huang X, Behera P, Husain S, Zhu T, Pan H, Jia Y, Settineri N, Giles-Donovan N, He Z, Scholl A, N'Diaye A, Shafer P, Raja A, Xu C, Martin LW, Crommie MF, Yao J, Qiu Z, Majumdar A, Bellaiche L, Muller DA, Birgeneau RJ, Ramesh R. Spin disorder control of topological spin texture. Nat Commun 2024; 15:3828. [PMID: 38714653 PMCID: PMC11076609 DOI: 10.1038/s41467-024-47715-5] [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: 01/24/2024] [Accepted: 04/10/2024] [Indexed: 05/10/2024] Open
Abstract
Stabilization of topological spin textures in layered magnets has the potential to drive the development of advanced low-dimensional spintronics devices. However, achieving reliable and flexible manipulation of the topological spin textures beyond skyrmion in a two-dimensional magnet system remains challenging. Here, we demonstrate the introduction of magnetic iron atoms between the van der Waals gap of a layered magnet, Fe3GaTe2, to modify local anisotropic magnetic interactions. Consequently, we present direct observations of the order-disorder skyrmion lattices transition. In addition, non-trivial topological solitons, such as skyrmioniums and skyrmion bags, are realized at room temperature. Our work highlights the influence of random spin control of non-trivial topological spin textures.
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Affiliation(s)
- Hongrui Zhang
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
| | - Yu-Tsun Shao
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA, 90089, USA
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
| | - Xiang Chen
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
- Department of Physics, University of California, Berkeley, CA, 94720, USA.
- Center for Neutron Science and Technology, School of Physics, Sun Yat-Sen University, Guangzhou, Guangdong, 510275, China.
| | - Binhua Zhang
- Key Laboratory of Computational Physical Sciences (Ministry of Education), Institute of Computational Physical Sciences, State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai, 200433, China
- Shanghai Qi Zhi Institute, Shanghai, 200030, China
| | - Tianye Wang
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Fanhao Meng
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Kun Xu
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Peter Meisenheimer
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Xianzhe Chen
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Xiaoxi Huang
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Piush Behera
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Sajid Husain
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Tiancong Zhu
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Hao Pan
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Yanli Jia
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Nick Settineri
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | | | - Zehao He
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Andreas Scholl
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Alpha N'Diaye
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Padraic Shafer
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Archana Raja
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Changsong Xu
- Key Laboratory of Computational Physical Sciences (Ministry of Education), Institute of Computational Physical Sciences, State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai, 200433, China.
- Shanghai Qi Zhi Institute, Shanghai, 200030, China.
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
- Department of Chemistry, Rice University, Houston, TX, 77005, USA
- Department of Physics and Astronomy, Rice University, Houston, TX, 77005, USA
- Rice Advanced Materials Institute, Rice University, Houston, TX, 77005, USA
| | - Michael F Crommie
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Jie Yao
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Ziqiang Qiu
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Arun Majumdar
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Laurent Bellaiche
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA
| | - David A Muller
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY, 14853, USA
| | - Robert J Birgeneau
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Ramamoorthy Ramesh
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
- Department of Physics, University of California, Berkeley, CA, 94720, USA.
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA.
- Department of Physics and Astronomy, Rice University, Houston, TX, 77005, USA.
- Rice Advanced Materials Institute, Rice University, Houston, TX, 77005, USA.
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12
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Wu H, Chen L, Malinowski P, Jang BG, Deng Q, Scott K, Huang J, Ruff JPC, He Y, Chen X, Hu C, Yue Z, Oh JS, Teng X, Guo Y, Klemm M, Shi C, Shi Y, Setty C, Werner T, Hashimoto M, Lu D, Yilmaz T, Vescovo E, Mo SK, Fedorov A, Denlinger JD, Xie Y, Gao B, Kono J, Dai P, Han Y, Xu X, Birgeneau RJ, Zhu JX, da Silva Neto EH, Wu L, Chu JH, Si Q, Yi M. Reversible non-volatile electronic switching in a near-room-temperature van der Waals ferromagnet. Nat Commun 2024; 15:2739. [PMID: 38548765 PMCID: PMC10978849 DOI: 10.1038/s41467-024-46862-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 03/13/2024] [Indexed: 04/01/2024] Open
Abstract
Non-volatile phase-change memory devices utilize local heating to toggle between crystalline and amorphous states with distinct electrical properties. Expanding on this kind of switching to two topologically distinct phases requires controlled non-volatile switching between two crystalline phases with distinct symmetries. Here, we report the observation of reversible and non-volatile switching between two stable and closely related crystal structures, with remarkably distinct electronic structures, in the near-room-temperature van der Waals ferromagnet Fe5-δGeTe2. We show that the switching is enabled by the ordering and disordering of Fe site vacancies that results in distinct crystalline symmetries of the two phases, which can be controlled by a thermal annealing and quenching method. The two phases are distinguished by the presence of topological nodal lines due to the preserved global inversion symmetry in the site-disordered phase, flat bands resulting from quantum destructive interference on a bipartite lattice, and broken inversion symmetry in the site-ordered phase.
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Affiliation(s)
- Han Wu
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Lei Chen
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Paul Malinowski
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Bo Gyu Jang
- Theoretical Division and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin, Republic of Korea
| | - Qinwen Deng
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Kirsty Scott
- Department of Physics, Yale University, New Haven, CT, USA
- Energy Sciences Institute, Yale University, West Haven, CT, USA
- Department of Physics and Astronomy, University of California, Davis, CA, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Jianwei Huang
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Jacob P C Ruff
- Cornell High Energy Synchrotron Source, Cornell University, Ithaca, NY, USA
| | - Yu He
- Department of Physics, University of California, Berkeley, CA, USA
| | - Xiang Chen
- Department of Physics, University of California, Berkeley, CA, USA
| | - Chaowei Hu
- Department of Physics, University of Washington, Seattle, WA, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Ziqin Yue
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Ji Seop Oh
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Xiaokun Teng
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Yucheng Guo
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Mason Klemm
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Chuqiao Shi
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA
| | - Yue Shi
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Chandan Setty
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Tyler Werner
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Makoto Hashimoto
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Donghui Lu
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Turgut Yilmaz
- National Synchrotron Light Source II, Brookhaven National Lab, Upton, NY, USA
| | - Elio Vescovo
- National Synchrotron Light Source II, Brookhaven National Lab, Upton, NY, USA
| | - Sung-Kwan Mo
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Alexei Fedorov
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Yaofeng Xie
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Bin Gao
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Junichiro Kono
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA
- Departments of Electrical and Computer Engineering, Rice University, Houston, TX, USA
| | - Pengcheng Dai
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Yimo Han
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, WA, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Robert J Birgeneau
- Department of Physics, University of California, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
| | - Jian-Xin Zhu
- Theoretical Division and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Eduardo H da Silva Neto
- Department of Physics, Yale University, New Haven, CT, USA
- Energy Sciences Institute, Yale University, West Haven, CT, USA
- Department of Physics and Astronomy, University of California, Davis, CA, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Liang Wu
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Jiun-Haw Chu
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Qimiao Si
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Ming Yi
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA.
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13
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Zhang H, Chen X, Wang T, Huang X, Chen X, Shao YT, Meng F, Meisenheimer P, N'Diaye A, Klewe C, Shafer P, Pan H, Jia Y, Crommie MF, Martin LW, Yao J, Qiu Z, Muller DA, Birgeneau RJ, Ramesh R. Room-Temperature, Current-Induced Magnetization Self-Switching in A Van Der Waals Ferromagnet. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2308555. [PMID: 38016700 DOI: 10.1002/adma.202308555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/30/2023] [Indexed: 11/30/2023]
Abstract
2D layered materials with broken inversion symmetry are being extensively pursued as spin source layers to realize high-efficiency magnetic switching. Such low-symmetry layered systems are, however, scarce. In addition, most layered magnets with perpendicular magnetic anisotropy show a low Curie temperature. Here, the experimental observation of spin-orbit torque magnetization self-switching at room temperature in a layered polar ferromagnetic metal, Fe2.5 Co2.5 GeTe2 is reported. The spin-orbit torque is generated from the broken inversion symmetry along the c-axis of the crystal. These results provide a direct pathway toward applicable 2D spintronic devices.
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Affiliation(s)
- Hongrui Zhang
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Xiang Chen
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Tianye Wang
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Xiaoxi Huang
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Xianzhe Chen
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Yu-Tsun Shao
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA, 90089, USA
| | - Fanhao Meng
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Peter Meisenheimer
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Alpha N'Diaye
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Christoph Klewe
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Padraic Shafer
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Hao Pan
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Yanli Jia
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Michael F Crommie
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Departments of Materials Science and NanoEngineering, Chemistry, and Physics and Astronomy, Rice University, Houston, TX, 77005, USA
- Rice Advanced Materials Institute, Rice University, Houston, TX, 77005, USA
| | - Jie Yao
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Ziqiang Qiu
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - David A Muller
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY, 14853, USA
| | - Robert J Birgeneau
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Ramamoorthy Ramesh
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Physics, University of California, Berkeley, CA, 94720, USA
- Department of Physics and Astronomy, Department of Materials Science and Nanoengineering, Rice University, Houston, TX, 77005, USA
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14
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Li Z, Zhang H, Li G, Guo J, Wang Q, Deng Y, Hu Y, Hu X, Liu C, Qin M, Shen X, Yu R, Gao X, Liao Z, Liu J, Hou Z, Zhu Y, Fu X. Room-temperature sub-100 nm Néel-type skyrmions in non-stoichiometric van der Waals ferromagnet Fe 3-xGaTe 2 with ultrafast laser writability. Nat Commun 2024; 15:1017. [PMID: 38310096 PMCID: PMC10838308 DOI: 10.1038/s41467-024-45310-2] [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: 08/08/2023] [Accepted: 01/19/2024] [Indexed: 02/05/2024] Open
Abstract
Realizing room-temperature magnetic skyrmions in two-dimensional van der Waals ferromagnets offers unparalleled prospects for future spintronic applications. However, due to the intrinsic spin fluctuations that suppress atomic long-range magnetic order and the inherent inversion crystal symmetry that excludes the presence of the Dzyaloshinskii-Moriya interaction, achieving room-temperature skyrmions in 2D magnets remains a formidable challenge. In this study, we target room-temperature 2D magnet Fe3GaTe2 and unveil that the introduction of iron-deficient into this compound enables spatial inversion symmetry breaking, thus inducing a significant Dzyaloshinskii-Moriya interaction that brings about room-temperature Néel-type skyrmions with unprecedentedly small size. To further enhance the practical applications of this finding, we employ a homemade in-situ optical Lorentz transmission electron microscopy to demonstrate ultrafast writing of skyrmions in Fe3-xGaTe2 using a single femtosecond laser pulse. Our results manifest the Fe3-xGaTe2 as a promising building block for realizing skyrmion-based magneto-optical functionalities.
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Grants
- This work was supported by the National Key Research and Development Program of China at grant No. 2020YFA0309300, Science and Technology Projects in Guangzhou (grant No. 202201000008), the National Natural Science Foundation of China (NSFC) at grant No. 12304146, 11974191, 12127803, 52322108, 52271178, U22A20117 and 12241403, China Postdoctoral Science Foundation (2023M741828), Guangdong Basic and Applied Basic Research Foundation (grant No. 2021B1515120047 and 2023B1515020112), the Natural Science Foundation of Tianjin at grant No. 20JCJQJC00210, the 111 Project at grant No. B23045, and the “Fundamental Research Funds for the Central Universities”, Nankai University (grant No. 63213040, C029211101, C02922101, ZB22000104 and DK2300010207). This work was supported by the Synergetic Extreme Condition User Facility (SECUF).
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Affiliation(s)
- Zefang Li
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Huai Zhang
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Guanqi Li
- School of Integrated Circuits, Guangdong University of Technology, Guangzhou, China
| | - Jiangteng Guo
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Qingping Wang
- School of Physics and Electronic and Electrical Engineering, Aba Teachers University, Wenchuan, China
| | - Ying Deng
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Yue Hu
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Xuange Hu
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Can Liu
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Minghui Qin
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Xi Shen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Richeng Yu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Xingsen Gao
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Zhimin Liao
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, China
| | - Junming Liu
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Zhipeng Hou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China.
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, USA.
| | - Xuewen Fu
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China.
- School of Materials Science and Engineering, Smart Sensing Interdisciplinary Science Center, Nankai University, Tianjin, China.
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15
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Zhang Y, Zhao K, Zheng S, Wang J, Zhang J, Feng Q, Wang Z, Gao J, Hou Y, Meng W, Lu Y, Lu Q. Glovebox-assisted magnetic force microscope for studying air-sensitive samples in a cryogen-free magnet. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:013701. [PMID: 38197772 DOI: 10.1063/5.0186587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 12/14/2023] [Indexed: 01/11/2024]
Abstract
Most known two-dimensional magnets exhibit a high sensitivity to air, making direct characterization of their domain textures technically challenging. Herein, we report on the construction and performance of a glovebox-assisted magnetic force microscope (MFM) operating in a cryogen-free magnet, realizing imaging of the intrinsic magnetic structure of water and oxygen-sensitive materials. It features a compact tubular probe for a 50 mm-diameter variable temperature insert installed in a 12 T cryogen-free magnet. A detachable sealing chamber can be electrically connected to the tail of the probe, and its pump port can be opened and closed by a vacuum manipulator located on the top of the probe. This sealing chamber enables sample loading and positioning in the glove box and MFM transfer to the magnet maintained in an inert gas atmosphere (in this case, argon and helium gas). The performance of the MFM is demonstrated by directly imaging the surface (using no buffer layer, such as h-BN) of very air-sensitive van der Waals magnetic material chromium triiodide (CrI3) samples at low temperatures as low as 5 K and high magnetic fields up to 11.9 T. The system's adaptability permits replacing the MFM unit with a scanning tunneling microscope unit, enabling high-resolution atomic imaging of air-sensitive surface samples.
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Affiliation(s)
- Yuchen Zhang
- University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Kesen Zhao
- University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- The High Magnetic Field Laboratory of Anhui Province, Hefei, Anhui 230031, People's Republic of China
| | - Shaofeng Zheng
- University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Jihao Wang
- Anhui Key Laboratory of Low-energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui 230031, People's Republic of China
- The High Magnetic Field Laboratory of Anhui Province, Hefei, Anhui 230031, People's Republic of China
| | - Jing Zhang
- Anhui Key Laboratory of Low-energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui 230031, People's Republic of China
- The High Magnetic Field Laboratory of Anhui Province, Hefei, Anhui 230031, People's Republic of China
| | - Qiyuan Feng
- Anhui Key Laboratory of Low-energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui 230031, People's Republic of China
- The High Magnetic Field Laboratory of Anhui Province, Hefei, Anhui 230031, People's Republic of China
| | - Ze Wang
- The High Magnetic Field Laboratory of Anhui Province, Hefei, Anhui 230031, People's Republic of China
| | - Jianhua Gao
- Anhui Key Laboratory of Low-energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui 230031, People's Republic of China
- The High Magnetic Field Laboratory of Anhui Province, Hefei, Anhui 230031, People's Republic of China
| | - Yubin Hou
- Anhui Key Laboratory of Low-energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui 230031, People's Republic of China
- The High Magnetic Field Laboratory of Anhui Province, Hefei, Anhui 230031, People's Republic of China
| | - Wenjie Meng
- Anhui Key Laboratory of Low-energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui 230031, People's Republic of China
- The High Magnetic Field Laboratory of Anhui Province, Hefei, Anhui 230031, People's Republic of China
| | - Yalin Lu
- University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Qingyou Lu
- University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- Anhui Key Laboratory of Low-energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui 230031, People's Republic of China
- The High Magnetic Field Laboratory of Anhui Province, Hefei, Anhui 230031, People's Republic of China
- Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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