1
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Lim S, Singh S, Huang FT, Pan S, Wang K, Kim J, Kim J, Vanderbilt D, Cheong SW. Magnetochiral tunneling in paramagnetic Co 1/3NbS 2. Proc Natl Acad Sci U S A 2024; 121:e2318443121. [PMID: 38412131 DOI: 10.1073/pnas.2318443121] [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: 10/24/2023] [Accepted: 01/25/2024] [Indexed: 02/29/2024] Open
Abstract
Electric currents have the intriguing ability to induce magnetization in nonmagnetic crystals with sufficiently low crystallographic symmetry. Some associated phenomena include the non-linear anomalous Hall effect in polar crystals and the nonreciprocal directional dichroism in chiral crystals when magnetic fields are applied. In this work, we demonstrate that the same underlying physics is also manifested in the electronic tunneling process between the surface of a nonmagnetic chiral material and a magnetized scanning probe. In the paramagnetic but chiral metallic compound Co1/3NbS2, the magnetization induced by the tunneling current is shown to become detectable by its coupling to the magnetization of the tip itself. This results in a contrast across different chiral domains, achieving atomic-scale spatial resolution of structural chirality. To support the proposed mechanism, we used first-principles theory to compute the chirality-dependent current-induced magnetization and Berry curvature in the bulk of the material. Our demonstration of this magnetochiral tunneling effect opens up an avenue for investigating atomic-scale variations in the local crystallographic symmetry and electronic structure across the structural domain boundaries of low-symmetry nonmagnetic crystals.
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Affiliation(s)
- Seongjoon Lim
- Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854
| | - Sobhit Singh
- Department of Mechanical Engineering, University of Rochester, Rochester, NY 14627
- Materials Science Program, University of Rochester, Rochester, NY 14627
| | - Fei-Ting Huang
- Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854
| | - Shangke Pan
- Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854
- State Key Laboratory Base of Novel Function Materials and Preparation Science, School of Material Sciences and Chemical Engineering, Ningbo University, Ningbo 315211, China
| | - Kefeng Wang
- Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854
| | - Jaewook Kim
- Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854
| | - Jinwoong Kim
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854
| | - David Vanderbilt
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854
| | - Sang-Wook Cheong
- Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854
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2
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Lawrence EA, Huai X, Kim D, Avdeev M, Chen Y, Skorupskii G, Miura A, Ferrenti A, Waibel M, Kawaguchi S, Ng N, Kaman B, Cai Z, Schoop L, Kushwaha S, Liu F, Tran TT, Ji H. Fe Site Order and Magnetic Properties of Fe 1/4NbS 2. Inorg Chem 2023; 62:18179-18188. [PMID: 37863841 DOI: 10.1021/acs.inorgchem.3c02652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2023]
Abstract
Transition-metal dichalcogenides (TMDs) have long been attractive to researchers for their diverse properties and high degree of tunability. Most recently, interest in magnetically intercalated TMDs has resurged due to their potential applications in spintronic devices. While certain compositions featuring the absence of inversion symmetry such as Fe1/3NbS2 and Cr1/3NbS2 have garnered the most attention, the diverse compositional space afforded through the host matrix composition as well as intercalant identity and concentration is large and remains relatively underexplored. Here, we report the magnetic ground state of Fe1/4NbS2 that was determined from low-temperature neutron powder diffraction as an A-type antiferromagnet. Despite the presence of overall inversion symmetry, the pristine compound manifests spin polarization induced by the antiferromagnetic order at generic k points, based on density functional theory band-structure calculations. Furthermore, by combining synchrotron diffraction, pair distribution function, and magnetic susceptibility measurements, we find that the magnetic properties of Fe1/4NbS2 are sensitive to the Fe site order, which can be tuned via electrochemical lithiation and thermal history.
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Affiliation(s)
- Erick A Lawrence
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
| | - Xudong Huai
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States
| | - Dongwook Kim
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
| | - Maxim Avdeev
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization, Kirrawee DC, New South Wales 2232, Australia
- School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Yu Chen
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Grigorii Skorupskii
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Akira Miura
- Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 8628, Japan
| | - Austin Ferrenti
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Moritz Waibel
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
- Faculty of Physics, Ludwig-Maximilians-University, Munich, Bavaria 80539, Germany
| | - Shogo Kawaguchi
- Japan Synchrotron Radiation Research Institute, Hyogo 679-5198 Japan
| | - Nicholas Ng
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Bobby Kaman
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Champaign, Illinois 61820, United States
| | - Zijian Cai
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Leslie Schoop
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Satya Kushwaha
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Feng Liu
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
| | - Thao T Tran
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States
| | - Huiwen Ji
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
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3
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Goodge B, Gonzalez O, Xie LS, Bediako DK. Consequences and Control of Multiscale Order/Disorder in Chiral Magnetic Textures. ACS NANO 2023; 17:19865-19876. [PMID: 37801330 PMCID: PMC10604074 DOI: 10.1021/acsnano.3c04203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 10/02/2023] [Indexed: 10/07/2023]
Abstract
Transition metal intercalated transition metal dichalcogenides (TMDs) are promising platforms for next-generation spintronic devices based on their wide range of electronic and magnetic phases, which can be tuned by varying the host lattice or intercalant's identity, stoichiometry, or spatial order. Some of these compounds host a chiral magnetic phase in which the helical winding of magnetic moments propagates along a high-symmetry crystalline axis. Previous studies have demonstrated that variation in intercalant concentrations can have a dramatic effect on the formation of chiral domains and ensemble magnetic properties. However, a systematic and comprehensive study of how atomic-scale order and disorder impact these chiral magnetic textures is so far lacking. Here, we leverage a combination of imaging modes in the (scanning) transmission electron microscope (S/TEM) to directly probe (dis)order across multiple length scales and show how subtle changes in the atomic lattice can tune the mesoscale spin textures and bulk magnetic response in Cr1/3NbS2, with direct implications for the fundamental understanding and technological implementation of such compounds.
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Affiliation(s)
- Berit
H. Goodge
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Max
Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Oscar Gonzalez
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Lilia S. Xie
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - D. Kwabena Bediako
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
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4
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Xie L, Gonzalez O, Li K, Michiardi M, Gorovikov S, Ryu SH, Fender SS, Zonno M, Jo NH, Zhdanovich S, Jozwiak C, Bostwick A, Husremović S, Erodici MP, Mollazadeh C, Damascelli A, Rotenberg E, Ping Y, Bediako DK. Comparative Electronic Structures of the Chiral Helimagnets Cr 1/3NbS 2 and Cr 1/3TaS 2. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:7239-7251. [PMID: 37719035 PMCID: PMC10500995 DOI: 10.1021/acs.chemmater.3c01564] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/03/2023] [Indexed: 09/19/2023]
Abstract
Magnetic materials with noncollinear spin textures are promising for spintronic applications. To realize practical devices, control over the length and energy scales of such spin textures is imperative. The chiral helimagnets Cr1/3NbS2 and Cr1/3TaS2 exhibit analogous magnetic-phase diagrams with different real-space periodicities and field dependence, positioning them as model systems for studying the relative strengths of the microscopic mechanisms giving rise to exotic spin textures. Although the electronic structure of the Nb analogue has been experimentally investigated, the Ta analogue has received far less attention. Here, we present a comprehensive suite of electronic structure studies on both Cr1/3NbS2 and Cr1/3TaS2 using angle-resolved photoemission spectroscopy and density functional theory. We show that bands in Cr1/3TaS2 are more dispersive than their counterparts in Cr1/3NbS2, resulting in markedly different Fermi wavevectors. The fact that their qualitative magnetic phase diagrams are nevertheless identical shows that hybridization between the intercalant and host lattice mediates the magnetic exchange interactions in both of these materials. We ultimately find that ferromagnetic coupling is stronger in Cr1/3TaS2, but larger spin-orbit coupling (and a stronger Dzyaloshinskii-Moriya interaction) from the heavier host lattice ultimately gives rise to shorter spin textures.
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Affiliation(s)
- Lilia
S. Xie
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Oscar Gonzalez
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Kejun Li
- Department
of Physics, University of California, Santa Cruz, California 95064, United States
| | - Matteo Michiardi
- Quantum
Matter Institute, University of British
Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department
of Physics and Astronomy, University of
British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Sergey Gorovikov
- Canadian
Light Source, Inc., 44
Innovation Boulevard, Saskatoon, Saskatchewan S7N 2V3, Canada
| | - Sae Hee Ryu
- Advanced
Light Source, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Shannon S. Fender
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Marta Zonno
- Canadian
Light Source, Inc., 44
Innovation Boulevard, Saskatoon, Saskatchewan S7N 2V3, Canada
| | - Na Hyun Jo
- Advanced
Light Source, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Department
of Physics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Sergey Zhdanovich
- Quantum
Matter Institute, University of British
Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department
of Physics and Astronomy, University of
British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Chris Jozwiak
- Advanced
Light Source, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Aaron Bostwick
- Advanced
Light Source, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Samra Husremović
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Matthew P. Erodici
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Cameron Mollazadeh
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Andrea Damascelli
- Quantum
Matter Institute, University of British
Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department
of Physics and Astronomy, University of
British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Eli Rotenberg
- Advanced
Light Source, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Yuan Ping
- Department
of Physics, University of California, Santa Cruz, California 95064, United States
- Department
of Materials Science and Engineering, University
of Wisconsin, Madison, Wisconsin 53706, United States
| | - D. Kwabena Bediako
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
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5
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Du K, Huang FT, Gamage K, Yang J, Mostovoy M, Cheong SW. Strain-Control of Cycloidal Spin Order in a Metallic Van der Waals Magnet. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2303750. [PMID: 37358066 DOI: 10.1002/adma.202303750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/06/2023] [Indexed: 06/27/2023]
Abstract
The manipulation of magnetism through strain control is a captivating area of research with potential applications for low-power devices that do not require dissipative currents. Recent investigations of insulating multiferroics have unveiled tunable relationships among polar lattice distortions, Dzyaloshinskii-Moriya interactions (DMI), and cycloidal spin orders that break inversion symmetry. These findings have raised the possibility of utilizing strain or strain gradient to manipulate intricate magnetic states by changing polarization. However, the effectiveness of manipulating cycloidal spin orders in "metallic" materials with screened magnetism-relevant electric polarization remains uncertain. In this study, the reversible strain control of cycloidal spin textures in a metallic van der Waals magnet, Cr1/3 TaS2 , through the modulation of polarization and DMI induced by strain is demonstrated. With thermally-induced biaxial strains and isothermally-applied uniaxial strains, systematic manipulation of the sign and wavelength of the cycloidal spin textures is realized, respectively. Additionally, unprecedented reflectivity reduction under strain and domain modification at a record-low current density are also discovered. These findings establish a connection between polarization and cycloidal spins in metallic materials and present a new avenue for utilizing the remarkable tunability of cycloidal magnetic textures and optical functionality in van der Waals metals with strain.
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Affiliation(s)
- Kai Du
- Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey, 08854, USA
| | - Fei-Ting Huang
- Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey, 08854, USA
| | - Kasun Gamage
- Department of Physics, New Jersey Institute of Technology, Newark, New Jersey, 07102, USA
| | - Junjie Yang
- Department of Physics, New Jersey Institute of Technology, Newark, New Jersey, 07102, USA
| | - Maxim Mostovoy
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, Groningen, 9747AG, The Netherlands
| | - Sang-Wook Cheong
- Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey, 08854, USA
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6
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Agarwal N, Sung SH, Schwartz J, Schnitzer N, Xi Z, Hung J, Baggari IE, Kourkoutis LF, Qi L, Van der Ven A, Hovden R. Native Intercalant Order in TaS2 Achieved Through in situ Thermal Heating. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:1583-1584. [PMID: 37613854 DOI: 10.1093/micmic/ozad067.814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Nishkarsh Agarwal
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Suk Hyun Sung
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Jonathan Schwartz
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Noah Schnitzer
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York, USA
| | - Zhucong Xi
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Juihung Hung
- Materials Department and Materials Research Laboratory, U.C. Santa Barbara, California, USA
| | | | - Lena F Kourkoutis
- Kavli Institute at Cornell, Cornell University, Ithaca, New York, USA
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York, USA
| | - Liang Qi
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Anton Van der Ven
- Materials Department and Materials Research Laboratory, U.C. Santa Barbara, California, USA
| | - Robert Hovden
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan, USA
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7
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Li L, Song D, Wang W, Zheng F, Kovács A, Tian M, Dunin-Borkowski RE, Du H. Transformation from Magnetic Soliton to Skyrmion in a Monoaxial Chiral Magnet. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2209798. [PMID: 36573473 DOI: 10.1002/adma.202209798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/17/2022] [Indexed: 06/18/2023]
Abstract
Topological spin textures are of great interest for both fundamental physics and applications in spintronics. The Dzyaloshinskii-Moriya interaction underpins the formation of single-twisted magnetic solitons or multi-twisted magnetic skyrmions in magnetic materials with different crystallographic symmetries. However, topological transitions between these two kinds of topological objects have not been verified experimentally. Here, the direct observation of transformations from a chiral soliton lattice (CSL) to magnetic skyrmions in a nanostripe of the monoaxial chiral magnet CrNb3 S6 using Lorentz transmission electron microscopy is reported. In the presence of an external magnetic field, helical spin structures first transform into CSLs and then evolve into isolated elongated magnetic skyrmions. The detailed spin textures of the elongated magnetic skyrmions are resolved using off-axis electron holography and are shown to comprise two merons, which enclose their ends and have unit total topological charge. Magnetic dipolar interactions are shown to play a key role in the magnetic soliton-skyrmion transformation, which depends sensitively on nanostripe width. The findings here, which are consistent with micromagnetic simulations, enrich the family of topological magnetic states and their transitions and promise to further stimulate the exploration of their emergent electromagnetic properties.
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Affiliation(s)
- Long Li
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
| | - Dongsheng Song
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China
- 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, Anhui, 230601, P. R. China
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Weiwei Wang
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China
- 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, Anhui, 230601, P. R. China
| | - Fengshan Zheng
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425, Jülich, Germany
- Spin-X Institute, Electron Microscopy Center, School of Physics and Optoelectronics, State Key Laboratory of Luminescent Materials and Devices, Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials, South China University of Technology, Guangzhou, 510006, P. R. China
| | - András Kovács
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Mingliang Tian
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
- School of Physics and Optoelectronics Engineering, Anhui University, Hefei, Anhui, 230601, P. R. China
| | - Rafal E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Haifeng Du
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
- 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, Anhui, 230601, P. R. China
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8
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Li Y, Wang X, Ma L. Instability of skyrmion lattice under microwave magnetic field due to single- qhelimagnetic excitation mode. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 35:105801. [PMID: 36538827 DOI: 10.1088/1361-648x/acad56] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Composed of the three spiral magnetic vectors, the structure of skyrmion lattice (SkL) can be destructed by spin excitations in possibly two ways: one is to make decoherence of all the helices through the phase change of a certain spiral magnetic vector, and the other is to inhibit one or two spiral components while enhancing the others so that it becomes a magnetic structure of single or double magnetic vectors. Here, we present a micromagnetic study on the spin excitations of a two-dimensional SkL under the in-plane microwave magnetic field. By calculating the parameters describing the in-plane spin excitations mode, we find that the spin configuration tends to be an enhanced single-vector spiral magnetic structure due to the excitation modes under some specific frequencies so that the SkL will collapse to the topologically trivial state. Our results help to form a deeper understanding of the spin excitation in SkL under an ac magnetic field.
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Affiliation(s)
- Yang Li
- Department of Physics, School of Science, Lanzhou University of Technology, Lanzhou 730050, People's Republic of China
| | - Xuan Wang
- Department of Physics, School of Science, Lanzhou University of Technology, Lanzhou 730050, People's Republic of China
| | - Leikai Ma
- Institute of Applied Magnetics, Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730030, People's Republic of China
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9
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Observation of Néel-type skyrmions in acentric self-intercalated Cr 1+δTe 2. Nat Commun 2022; 13:3965. [PMID: 35803924 PMCID: PMC9270380 DOI: 10.1038/s41467-022-31319-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 06/14/2022] [Indexed: 11/21/2022] Open
Abstract
Transition-metal dichalcogenides intercalated with 3d-transition metals within the van der Waals (vdW) gaps have been the focus of intense investigations owing to their fascinating structural and magnetic properties. At certain concentrations the intercalated atoms form ordered superstructures that exhibit ferromagnetic or anti-ferromagnetic ordering. Here we show that the self-intercalated compound Cr1+δTe2 with δ ≈ 0.3 exhibits a new, so far unseen, three-dimensionally ordered (2×2×2) superstructure. Furthermore, high resolution X-ray diffraction reveals that there is an asymmetric occupation of the two inequivalent vdW gaps in the unit cell. The structure thus lacks inversion symmetry, which, thereby, allows for chiral non-collinear magnetic nanostructures. Indeed, Néel-type skyrmions are directly observed using Lorentz transmission electron microscopy. The skyrmions are stable within the accessible temperature range (100–200 K) as well as in zero magnetic field. The diameter of the Néel skyrmions increases with lamella thickness and varies with applied magnetic field, indicating the role of long-range dipole fields. Our studies show that self-intercalation in vdW materials is a novel route to the formation of synthetic non-collinear spin textures. Here, Saha et al. show that self-intercalation of e2Cr atoms in CrTe2 create an asymmetry in the number of atoms intercalated in the van der Waals gaps between the layers of CrTe2. This inversion symmetry breaking leads to non-collinear spin-textures and Néel-type magnetic skyrmions over a wide temperature range.
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10
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Xie LS, Husremović S, Gonzalez O, Craig IM, Bediako DK. Structure and Magnetism of Iron- and Chromium-Intercalated Niobium and Tantalum Disulfides. J Am Chem Soc 2022; 144:9525-9542. [PMID: 35584537 DOI: 10.1021/jacs.1c12975] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Transition metal dichalcogenides (TMDs) intercalated with spin-bearing transition metal centers are a diverse class of magnetic materials where the spin density and ordering behavior can be varied by the choice of host lattice, intercalant identity, level of intercalation, and intercalant disorder. Each of these degrees of freedom alters the interplay between several key magnetic interactions to produce disparate collective electronic and magnetic phases. The array of magnetic and electronic behavior typified by these systems renders them distinctive platforms for realizing tunable magnetism in solid-state materials and promising candidates for spin-based electronic devices. This Perspective provides an overview of the rich magnetism displayed by transition metal-intercalated TMDs by considering Fe- and Cr-intercalated NbS2 and TaS2. These four exemplars of this large family of materials exhibit a wide range of magnetic properties, including sharp switching of magnetic states, current-driven magnetic switching, and chiral spin textures. An understanding of the fundamental origins of the resultant magnetic/electronic phases in these materials is discussed in the context of composition, bonding, electronic structure, and magnetic anisotropy in each case study.
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Affiliation(s)
- Lilia S Xie
- Department of Chemistry, University of California, Berkeley, California 97420, United States
| | - Samra Husremović
- Department of Chemistry, University of California, Berkeley, California 97420, United States
| | - Oscar Gonzalez
- Department of Chemistry, University of California, Berkeley, California 97420, United States
| | - Isaac M Craig
- Department of Chemistry, University of California, Berkeley, California 97420, United States
| | - D Kwabena Bediako
- Department of Chemistry, University of California, Berkeley, California 97420, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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