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Makarov AY, Buravlev AA, Romanenko GV, Bogomyakov AS, Zakharov BA, Morozov VA, Sukhikh AS, Shundrina IK, Shundrin LA, Irtegova IG, Cherepanova SV, Bagryanskaya IY, Nikulshin PV, Zibarev AV. Hysteretic Room-Temperature Magnetic Bistability of the Crystalline 4,7-Difluoro-1,3,2-Benzodithiazolyl Radical. Chempluschem 2024; 89:e202300736. [PMID: 38332534 DOI: 10.1002/cplu.202300736] [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: 12/13/2023] [Revised: 02/08/2024] [Accepted: 02/08/2024] [Indexed: 02/10/2024]
Abstract
The title radical R⋅, synthesized by reduction of the corresponding cation R+, is thermally stable up to ~380 K in the crystalline state under anaerobic conditions. With SQUID magnetometry, single-crystal and powder XRD, solid-state EPR and TG-DSC, reversible spin-Peierls transition between diamagnetic and paramagnetic states featuring ~10 K hysteretic loop is observed for R⋅ in the temperature range ~310-325 K; ΔH=~2.03 kJ mol-1 and ΔS=~6.23 J mol-1 K-1. The transition is accompanied by mechanical movement of the crystals, i. e., by thermosalient behavior. The low-temperature diamagnetic P-1 polymorph of R⋅ consists of R⋅2 π-dimers arranged in (…R⋅2…)n π-stacks; whereas the high-temperature paramagnetic P21/c polymorph, of uniform (…R⋅…)n π-stacks. With the XRD geometries, CASSCF and broken-symmetry DFT jointly suggest strong antiferromagnetic (AF) interactions within R⋅2 and weak between R⋅2 for the (…R⋅2…)n stacks; and moderate AF interactions between R⋅ for the (…R⋅…)n stacks. The fully hydrocarbon archetype of R⋅ does not reveal the aforementioned properties. Thus, the fluorinated 1,3,2-benzodithiazolyls pave a new pathway in the design and synthesis of metal-less magnetically-bistable materials.
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Affiliation(s)
- Alexander Yu Makarov
- Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Alexander A Buravlev
- Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
- Department of Natural Sciences National Research University, Novosibirsk State University, 630090, Novosibirsk, Russia
| | - Galina V Romanenko
- International Tomography Center, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Artem S Bogomyakov
- International Tomography Center, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Boris A Zakharov
- Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
- Department of Natural Sciences National Research University, Novosibirsk State University, 630090, Novosibirsk, Russia
| | - Vitaly A Morozov
- International Tomography Center, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Alexander S Sukhikh
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
- Department of Physics, National Research University - Novosibirsk State University, 630090, Novosibirsk, Russia
| | - Inna K Shundrina
- Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Leonid A Shundrin
- Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Irina G Irtegova
- Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Svetlana V Cherepanova
- Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Irina Yu Bagryanskaya
- Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Pavel V Nikulshin
- Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
- Current address: Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 119991, Moscow, Russia
| | - Andrey V Zibarev
- Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia
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Wang ZQ, Xue F, Qiu L, Wang Z, Wu R, Hou Y. Switching Intrinsic Magnetic Skyrmions with Controllable Magnetic Anisotropy in van der Waals Multiferroic Heterostructures. NANO LETTERS 2024; 24:4117-4123. [PMID: 38509030 DOI: 10.1021/acs.nanolett.3c05024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Magnetic skyrmions, topologically nontrivial whirling spin textures at nanometer scales, have emerged as potential information carriers for spintronic devices. The ability to efficiently create and erase magnetic skyrmions is vital yet challenging for such applications. Based on first-principles studies, we find that switching between intrinsic magnetic skyrmion and high-temperature ferromagnetic states can be achieved in the two-dimensional van der Waals (vdW) multiferroic heterostructure CrSeI/In2Te3 by reversing the ferroelectric polarization of In2Te3. The core mechanism of this switching is traced to the controllable magnetic anisotropy of CrSeI influenced by the ferroelectric polarization of In2Te3. We propose a useful descriptor linking the presence of magnetic skyrmions to magnetic parameters and validate this connection through studies of a variety of similar vdW multiferroic heterostructures. Our work demonstrates that manipulating magnetic skyrmions via tunable magnetic anisotropies in vdW multiferroic heterostructures represents a highly promising and energy-efficient strategy for the future development of spintronics.
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Affiliation(s)
- Ze-Quan Wang
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Center for Neutron Science and Technology, School of Physics, Sun Yat-Sen University, Guangzhou 510275, China
| | - Feng Xue
- Department of Physics, College of Physics & Optoelectronic Engineering, Jinan University, Guangzhou, Guangdong 510632, China
| | - Liang Qiu
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Center for Neutron Science and Technology, School of Physics, Sun Yat-Sen University, Guangzhou 510275, China
| | - Zhe Wang
- Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697-4575, United States
| | - Ruqian Wu
- Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697-4575, United States
| | - Yusheng Hou
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Center for Neutron Science and Technology, School of Physics, Sun Yat-Sen University, Guangzhou 510275, China
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Chen H, Asif S, Dolui K, Wang Y, Támara-Isaza J, Goli VMLDP, Whalen M, Wang X, Chen Z, Zhang H, Liu K, Jariwala D, Jungfleisch MB, Chakraborty C, May AF, McGuire MA, Nikolic BK, Xiao JQ, Ku MJH. Above-Room-Temperature Ferromagnetism in Thin van der Waals Flakes of Cobalt-Substituted Fe 5GeTe 2. ACS APPLIED MATERIALS & INTERFACES 2023; 15:3287-3296. [PMID: 36602594 DOI: 10.1021/acsami.2c18028] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Two-dimensional (2D) magnetic van der Waals materials provide a powerful platform for studying the fundamental physics of low-dimensional magnetism, engineering novel magnetic phases, and enabling thin and highly tunable spintronic devices. To realize high-quality and practical devices for such applications, there is a critical need for robust 2D magnets with ordering temperatures above room temperature that can be created via exfoliation. Here, the study of exfoliated flakes of cobalt-substituted Fe5GeTe2 (CFGT) exhibiting magnetism above room temperature is reported. Via quantum magnetic imaging with nitrogen-vacancy centers in diamond, ferromagnetism at room temperature was observed in CFGT flakes as thin as 16 nm corresponding to 16 layers. This result expands the portfolio of thin room-temperature 2D magnet flakes exfoliated from robust single crystals that reach a thickness regime relevant to practical spintronic applications. The Curie temperature Tc of CFGT ranges from 310 K in the thinnest flake studied to 328 K in the bulk. To investigate the prospect of high-temperature monolayer ferromagnetism, Monte Carlo calculations were performed, which predicted a high value of Tc of ∼270 K in CFGT monolayers. Pathways toward further enhancing monolayer Tc are discussed. These results support CFGT as a promising platform for realizing high-quality room-temperature 2D magnet devices.
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Affiliation(s)
- Hang Chen
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Shahidul Asif
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware19716, United States
| | - Kapildeb Dolui
- Lomare Technologies Ltd., 6 London Street, LondonEC3R 7LP, United Kingdom
| | - Yang Wang
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Jeyson Támara-Isaza
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
- Departamento de Física, Universidad Nacional de Colombia, Bogotá D.C.110851, Colombia
| | - V M L Durga Prasad Goli
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Matthew Whalen
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Xinhao Wang
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Zhijie Chen
- Department of Physics, Georgetown University, Washington, District of Columbia20057, United States
| | - Huiqin Zhang
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
| | - Kai Liu
- Department of Physics, Georgetown University, Washington, District of Columbia20057, United States
| | - Deep Jariwala
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
| | - M Benjamin Jungfleisch
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Chitraleema Chakraborty
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware19716, United States
| | - Andrew F May
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Michael A McGuire
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Branislav K Nikolic
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - John Q Xiao
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
| | - Mark J H Ku
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware19716, United States
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware19716, United States
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Review on Magnetism in Catalysis: From Theory to PEMFC Applications of 3d Metal Pt-Based Alloys. Int J Mol Sci 2022; 23:ijms232314768. [PMID: 36499096 PMCID: PMC9739051 DOI: 10.3390/ijms232314768] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
The relationship between magnetism and catalysis has been an important topic since the mid-20th century. At present time, the scientific community is well aware that a full comprehension of this relationship is required to face modern challenges, such as the need for clean energy technology. The successful use of (para-)magnetic materials has already been corroborated in catalytic processes, such as hydrogenation, Fenton reaction and ammonia synthesis. These catalysts typically contain transition metals from the first to the third row and are affected by the presence of an external magnetic field. Nowadays, it appears that the most promising approach to reach the goal of a more sustainable future is via ferromagnetic conducting catalysts containing open-shell metals (i.e., Fe, Co and Ni) with extra stabilization coming from the presence of an external magnetic field. However, understanding how intrinsic and extrinsic magnetic features are related to catalysis is still a complex task, especially when catalytic performances are improved by these magnetic phenomena. In the present review, we introduce the relationship between magnetism and catalysis and outline its importance in the production of clean energy, by describing the representative case of 3d metal Pt-based alloys, which are extensively investigated and exploited in PEM fuel cells.
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Absence of Spin Frustration in the Kagomé Layers of Cu2+ Ions in Volborthite Cu3V2O7(OH)2·2H2O and Observation of the Suppression and Re-Entrance of Specific Heat Anomalies in Volborthite under an External Magnetic Field. CONDENSED MATTER 2022. [DOI: 10.3390/condmat7010024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We determined the spin exchanges between the Cu2+ ions in the kagomé layers of volborthite, Cu3V2O7(OH)2·2H2O, by performing the energy-mapping analysis based on DFT+U calculations, to find that the kagomé layers of Cu2+ ions are hardly spin-frustrated, and the magnetic properties of volborthite below ~75 K should be described by very weakly interacting antiferromagnetic uniform chains made up of effective S = 1/2 pseudospin units. This conclusion was verified by synthesizing single crystals of not only Cu3V2O7(OH)2·2H2O but also its deuterated analogue Cu3V2O7(OD)2·2D2O and then by investigating their magnetic susceptibilities and specific heats. Each kagomé layer consists of intertwined two-leg spin ladders with rungs of linear spin trimers. With the latter acting as S = 1/2 pseudospin units, each two-leg spin ladder behaves as a chain of S = 1/2 pseudospins. Adjacent two-leg spin ladders in each kagomé layer interact very weakly, so it is required that all nearest-neighbor spin exchange paths of every two-leg spin ladder remain antiferromagnetically coupled in all spin ladder arrangements of a kagomé layer. This constraint imposes three sets of entropy spectra with which each kagomé layer can exchange energy with the surrounding on lowering the temperature below ~1.5 K and on raising the external magnetic field B. We discovered that the specific heat anomalies of volborthite observed below ~1.5 K at B = 0 are suppressed by raising the magnetic field B to ~4.2 T, that a new specific heat anomaly occurs when B is increased above ~5.5 T, and that the imposed three sets of entropy spectra are responsible for the field-dependence of the specific heat anomalies.
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Almoussawi B, Duffort V, Arevalo-Lopez AM, Braun M, Djelal N, Kabbour H. Preparation, characterization and DFT+U study of the polar Fe 3+-based phase Ba 5Fe 2ZnIn 4S 15 containing S= 5/2 zigzag chains. Dalton Trans 2022; 51:9522-9530. [DOI: 10.1039/d2dt00733a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The polar magnetic chalcogenide phase Ba5Fe2ZnIn4S15 was synthesized and its structure solved from single crystal XRD. It is the first member with a 3d magnetic metal (Fe3+) in the Pb5ZnGa6S15-type...
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Etourneau J, Delmas C, Jobic S, Whangbo MH. In Honor of John Bannister Goodenough, an Outstanding Visionary. Molecules 2021; 26:molecules26216624. [PMID: 34771033 PMCID: PMC8587107 DOI: 10.3390/molecules26216624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/24/2021] [Accepted: 10/25/2021] [Indexed: 11/22/2022] Open
Affiliation(s)
- Jean Etourneau
- ICMCB-CNRS, University of Bordeaux, 33600 Pessac, France;
- Correspondence: (J.E.); (M.-H.W.)
| | - Claude Delmas
- ICMCB-CNRS, University of Bordeaux, 33600 Pessac, France;
| | - Stéphane Jobic
- Institut des Matériaux Jean Rouxel, Université de Nantes, CNRS, IMN, 44000 Nantes, France;
| | - Myung-Hwan Whangbo
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
- Correspondence: (J.E.); (M.-H.W.)
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Živković A, King HE, Wolthers M, de Leeuw NH. Magnetic structure and exchange interactions in pyrrhotite end member minerals: hexagonal FeS and monoclinic Fe 7S 8. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:465801. [PMID: 34380113 DOI: 10.1088/1361-648x/ac1cb2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Iron mono-sulphides, or pyrrhotites, are minerals present in the Earth's crust and mantle as well as major magnetic constituents of several classes of meteorites, thus are of interest to a wide range of disciplines including geology, geophysics, geochemistry, and material science. Despite displaying diverse magnetic properties as a result of iron vacancy ordering, the underlying exchange mechanism has not been quantified. This study presents an examination of the electronic and magnetic properties for the two pyrrhotite group end members, hexagonal FeS and monoclinic Fe7S8(4C superstructure) by means of density functional theory coupled with a Heisenberg magnetic model. The easy magnetization axes of FeS and Fe7S8are found to be positioned along the crystallographicc-direction and at an angle of 56° to thec-direction, respectively. The magnetic anisotropy energy in Fe7S8is greatly increased as a consequence of the vacancy framework when compared to FeS. The main magnetic interaction, in both compounds, is found to be the isotropic exchange interaction favouring antiferromagnetic alignment between nearest-neighbouring spins. The origin of the exchange interaction is elucidated further following the Goodenough-Kanamori-Anderson rules. The antisymmetric spin exchange is found to have a minor effect in both compounds. The theoretical findings presented in this work thus help to further resolve some of the ambiguities in the magnetic features of pyrrhotites.
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Affiliation(s)
- Aleksandar Živković
- Department of Earth Sciences, Utrecht University, Princetonlaan 8a, 3584CB Utrecht, The Netherlands
| | - Helen E King
- Department of Earth Sciences, Utrecht University, Princetonlaan 8a, 3584CB Utrecht, The Netherlands
| | - Mariette Wolthers
- Department of Earth Sciences, Utrecht University, Princetonlaan 8a, 3584CB Utrecht, The Netherlands
| | - Nora H de Leeuw
- Department of Earth Sciences, Utrecht University, Princetonlaan 8a, 3584CB Utrecht, The Netherlands
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
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Hayami S, Motome Y. Topological spin crystals by itinerant frustration. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:443001. [PMID: 34343975 DOI: 10.1088/1361-648x/ac1a30] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 08/03/2021] [Indexed: 06/13/2023]
Abstract
Spin textures with nontrivial topology, such as vortices and skyrmions, have attracted attention as a source of unconventional magnetic, transport, and optical phenomena. Recently, a new generation of topological spin textures has been extensively studied in itinerant magnets; in contrast to the conventional ones induced, e.g., by the Dzyaloshinskii-Moriya interaction in noncentrosymmetric systems, they are characterized by extremely short magnetic periods and stable even in centrosymmetric systems. Here we review such new types of topological spin textures with particular emphasis on their stabilization mechanism. Focusing on the interplay between charge and spin degrees of freedom in itinerant electron systems, we show that itinerant frustration, which is the competition among electron-mediated interactions, plays a central role in stabilizing a variety of topological spin crystals including a skyrmion crystal with unconventional high skyrmion number, meron crystals, and hedgehog crystals. We also show that the essential ingredients in the itinerant frustration are represented by bilinear and biquadratic spin interactions in momentum space. This perspective not only provides a unified understanding of the unconventional topological spin crystals but also stimulates further exploration of exotic topological phenomena in itinerant magnets.
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Affiliation(s)
- Satoru Hayami
- Department of Applied Physics, University of Tokyo, Bunkyo, Tokyo 113-8656, Japan
| | - Yukitoshi Motome
- Department of Applied Physics, University of Tokyo, Bunkyo, Tokyo 113-8656, Japan
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