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Roychowdhury S, Samanta K, Singh S, Schnelle W, Zhang Y, Noky J, Vergniory MG, Shekhar C, Felser C. Enhancement of the anomalous Hall effect by distorting the Kagome lattice in an antiferromagnetic material. Proc Natl Acad Sci U S A 2024; 121:e2401970121. [PMID: 39008668 DOI: 10.1073/pnas.2401970121] [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: 01/29/2024] [Accepted: 06/06/2024] [Indexed: 07/17/2024] Open
Abstract
In topological magnetic materials, the topology of the electronic wave function is strongly coupled to the structure of the magnetic order. In general, ferromagnetic Weyl semimetals generate a strong anomalous Hall conductivity (AHC) due to a large Berry curvature that scales with their magnetization. In contrast, a comparatively small AHC is observed in noncollinear antiferromagnets. We investigated HoAgGe, an antiferromagnetic (AFM) Kagome spin-ice compound, which crystallizes in a hexagonal ZrNiAl-type structure in which Ho atoms are arranged in a distorted Kagome lattice, forming an intermetallic Kagome spin-ice state in the ab-plane. It exhibits a large topological Hall resistivity of ~1.6 µΩ-cm at 2.0 K in a field of ~3 T owing to the noncoplanar structure. Interestingly, a total AHC of 2,800 Ω-1 cm-1 is observed at ~45 K, i.e., 4 TN, which is quite unusual and goes beyond the normal expectation considering HoAgGe as an AFM Kagome spin-ice compound with a TN of ~11 K. We demonstrate further that the AHC below TN results from the nonvanishing Berry curvature generated by the formation of Weyl points under the influence of the external magnetic field, while the skew scattering led by Kagome spins dominates above the TN. These results offer a unique opportunity to study frustration in AFM Kagome lattice compounds.
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Affiliation(s)
- Subhajit Roychowdhury
- Department of Topological Quantum Chemistry, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal 462066, India
| | - Kartik Samanta
- Department of Topological Quantum Chemistry, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Sukriti Singh
- Department of Topological Quantum Chemistry, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Walter Schnelle
- Department of Topological Quantum Chemistry, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Yang Zhang
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996
- Min H. Kao Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, TN 37996
| | - Jonathan Noky
- Department of Topological Quantum Chemistry, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Maia G Vergniory
- Department of Topological Quantum Chemistry, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Donostia International Physics Center, Donostia-San Sebastian 20018, Spain
| | - Chandra Shekhar
- Department of Topological Quantum Chemistry, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Claudia Felser
- Department of Topological Quantum Chemistry, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
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2
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Manako H, Ohsumi S, Sato YJ, Okazaki R, Aoki D. Large transverse thermoelectric effect induced by the mixed-dimensionality of Fermi surfaces. Nat Commun 2024; 15:3907. [PMID: 38724529 PMCID: PMC11081953 DOI: 10.1038/s41467-024-48217-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 04/24/2024] [Indexed: 05/12/2024] Open
Abstract
Transverse thermoelectric effect, the conversion of longitudinal heat current into transverse electric current, or vice versa, offers a promising energy harvesting technology. Materials with axis-dependent conduction polarity, known as p × n-type conductors or goniopolar materials, are potential candidate, because the non-zero transverse elements of thermopower tensor appear under rotational operation, though the availability is highly limited. Here, we report that a ternary metal LaPt2B with unique crystal structure exhibits axis-dependent thermopower polarity, which is driven by mixed-dimensional Fermi surfaces consisting of quasi-one-dimensional hole sheet with out-of-plane velocity and quasi-two-dimensional electron sheets with in-plane velocity. The ideal mixed-dimensional conductor LaPt2B exhibits an extremely large transverse Peltier conductivity up to ∣αyx∣ = 130 A K-1 m-1, and its transverse thermoelectric performance surpasses those of topological magnets utilizing the anomalous Nernst effect. These results thus manifest the mixed-dimensionality as a key property for efficient transverse thermoelectric conversion.
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Affiliation(s)
- Hikari Manako
- Department of Physics and Astronomy, Tokyo University of Science, Noda, Japan
| | - Shoya Ohsumi
- Department of Physics and Astronomy, Tokyo University of Science, Noda, Japan
| | - Yoshiki J Sato
- Department of Physics and Astronomy, Tokyo University of Science, Noda, Japan.
- Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
| | - R Okazaki
- Department of Physics and Astronomy, Tokyo University of Science, Noda, Japan
| | - D Aoki
- Institute for Materials Research, Tohoku University, Oarai, Ibaraki, Japan
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3
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Zhou W, Sasaki T, Uchida K, Sakuraba Y. Direct-Contact Seebeck-Driven Transverse Magneto-Thermoelectric Generation in Magnetic/Thermoelectric Bilayers. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2308543. [PMID: 38447187 PMCID: PMC11095155 DOI: 10.1002/advs.202308543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/07/2024] [Indexed: 03/08/2024]
Abstract
Transverse thermoelectric generation converts temperature gradient in one direction into an electric field perpendicular to that direction and is expected to be a promising alternative in creating simple-structured thermoelectric modules that can avoid the challenging problems facing traditional Seebeck-effect-based modules. Recently, large transverse thermopower has been observed in closed circuits consisting of magnetic and thermoelectric materials, called the Seebeck-driven transverse magneto-thermoelectric generation (STTG). However, the closed-circuit structure complicates its broad applications. Here, STTG is realized in the simplest way to combine magnetic and thermoelectric materials, namely, by stacking a magnetic layer and a thermoelectric layer together to form a bilayer. The transverse thermopower is predicted to vary with changing layer thicknesses and peaks at a much larger value under an optimal thickness ratio. This behavior is verified in the experiment, through a series of samples prepared by depositing Fe-Ga alloy thin films of various thicknesses onto n-type Si substrates. The measured transverse thermopower reaches 15.2 ± 0.4 µV K-1, which is a fivefold increase from that of Fe-Ga alloy and much larger than the current room temperature record observed in Weyl semimetal Co2MnGa. The findings highlight the potential of combining magnetic and thermoelectric materials for transverse thermoelectric applications.
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Affiliation(s)
- Weinan Zhou
- International Center for Young ScientistsNational Institute for Materials ScienceTsukuba305‐0047Japan
| | - Taisuke Sasaki
- Research Center for Magnetic and Spintronic MaterialsNational Institute for Materials ScienceTsukuba305‐0047Japan
| | - Ken‐ichi Uchida
- Research Center for Magnetic and Spintronic MaterialsNational Institute for Materials ScienceTsukuba305‐0047Japan
| | - Yuya Sakuraba
- Research Center for Magnetic and Spintronic MaterialsNational Institute for Materials ScienceTsukuba305‐0047Japan
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4
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Dey A, Pradhan J, Biswas S, Ahamed Rahimi F, Biswas K, Maji TK. COF-Topological Quantum Material Nano-heterostructure for CO 2 to Syngas Production under Visible Light. Angew Chem Int Ed Engl 2024; 63:e202315596. [PMID: 38400778 DOI: 10.1002/anie.202315596] [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: 10/16/2023] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 02/26/2024]
Abstract
Efficient solar-driven syngas production (CO+H2 mixture) from CO2 and H2O with a suitable photocatalyst and fundamental understanding of the reaction mechanism are the desired approach towards the carbon recycling process. Herein, we report the design and development of an unique COF-topological quantum material nano-heterostructure, COF@TI with a newly synthesized donor-acceptor based COF and two dimensional (2D) nanosheets of strong topological insulator (TI), PbBi2Te4. The intrinsic robust metallic surfaces of the TI act as electron reservoir, minimising the fast electron-hole recombination process, and the presence of 6s2 lone pairs in Pb2+ and Bi3+ in the TI helps for efficient CO2 binding, which are responsible for boosting overall catalytic activity. In variable ratio of acetonitrile-water (MeCN : H2O) solvent mixture COF@TI produces syngas with different ratios of CO and H2. COF@TI nano-heterostructure enables to produce higher amount of syngas with more controllable ratios of CO and H2 compared to pristine COF. The electron transfer route from COF to TI was realized from Kelvin probe force microscopy (KPFM) analysis, charge density difference calculation, excited state lifetime and photoelectrochemical measurements. Finally, a probable mechanistic pathway has been established after identifying the catalytic sites and reaction intermediates by in situ DRIFTS study and DFT calculation.
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Affiliation(s)
- Anupam Dey
- Chemistry and Physics of Materials Unit (CPMU), School of Advanced Materials (SAMat), International Centre for Materials Science (ICMS), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), 560064, Jakkur, Bangalore, India
| | - Jayita Pradhan
- New Chemistry Unit (NCU), School of Advanced Materials (SAMat), International Centre for Materials Science (ICMS), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), 560064, Jakkur, Bangalore, India
| | - Sandip Biswas
- Chemistry and Physics of Materials Unit (CPMU), School of Advanced Materials (SAMat), International Centre for Materials Science (ICMS), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), 560064, Jakkur, Bangalore, India
| | - Faruk Ahamed Rahimi
- Chemistry and Physics of Materials Unit (CPMU), School of Advanced Materials (SAMat), International Centre for Materials Science (ICMS), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), 560064, Jakkur, Bangalore, India
| | - Kanishka Biswas
- New Chemistry Unit (NCU), School of Advanced Materials (SAMat), International Centre for Materials Science (ICMS), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), 560064, Jakkur, Bangalore, India
| | - Tapas Kumar Maji
- Chemistry and Physics of Materials Unit (CPMU), School of Advanced Materials (SAMat), International Centre for Materials Science (ICMS), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), 560064, Jakkur, Bangalore, India
- New Chemistry Unit (NCU), School of Advanced Materials (SAMat), International Centre for Materials Science (ICMS), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), 560064, Jakkur, Bangalore, India
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5
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Wu W, Shi Z, Ozerov M, Du Y, Wang Y, Ni XS, Meng X, Jiang X, Wang G, Hao C, Wang X, Zhang P, Pan C, Pan H, Sun Z, Yang R, Xu Y, Hou Y, Yan Z, Zhang C, Lu HZ, Chu J, Yuan X. The discovery of three-dimensional Van Hove singularity. Nat Commun 2024; 15:2313. [PMID: 38485978 PMCID: PMC10940667 DOI: 10.1038/s41467-024-46626-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 02/29/2024] [Indexed: 03/18/2024] Open
Abstract
Arising from the extreme/saddle point in electronic bands, Van Hove singularity (VHS) manifests divergent density of states (DOS) and induces various new states of matter such as unconventional superconductivity. VHS is believed to exist in one and two dimensions, but rarely found in three dimension (3D). Here, we report the discovery of 3D VHS in a topological magnet EuCd2As2 by magneto-infrared spectroscopy. External magnetic fields effectively control the exchange interaction in EuCd2As2, and shift 3D Weyl bands continuously, leading to the modification of Fermi velocity and energy dispersion. Above the critical field, the 3D VHS forms and is evidenced by the abrupt emergence of inter-band transitions, which can be quantitatively described by the minimal model of Weyl semimetals. Three additional optical transitions are further predicted theoretically and verified in magneto-near-infrared spectra. Our results pave the way to exploring VHS in 3D systems and uncovering the coordination between electronic correlation and the topological phase.
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Affiliation(s)
- Wenbin Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
- Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
- Shanghai Center of Brain-Inspired Intelligent Materials and Devices, East China Normal University, 200241, Shanghai, China
| | - Zeping Shi
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Yuhan Du
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Yuxiang Wang
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, 200433, Shanghai, China
| | - Xiao-Sheng Ni
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Xianghao Meng
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Xiangyu Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Guangyi Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Congming Hao
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Xinyi Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Pengcheng Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Chunhui Pan
- Multifunctional Platform for Innovation Precision Machining Center, East China Normal University, 200241, Shanghai, China
| | - Haifeng Pan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Zhenrong Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Run Yang
- Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, 211189, Nanjing, China
| | - Yang Xu
- Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
| | - Yusheng Hou
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Zhongbo Yan
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Cheng Zhang
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, 200433, Shanghai, China
- Zhangjiang Fudan International Innovation Center, Fudan University, 201210, Shanghai, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), 518055, Shenzhen, China
| | - Junhao Chu
- Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
- Institute of Optoelectronics, Fudan University, 200438, Shanghai, China
| | - Xiang Yuan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China.
- Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China.
- Shanghai Center of Brain-Inspired Intelligent Materials and Devices, East China Normal University, 200241, Shanghai, China.
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6
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Khan I, Marfoua B, Hong J. Optical transparency in 2D ferromagnetic WSe 2/1T-VSe 2/WSe 2multilayer with strain induced large anomalous Nernst conductivity. NANOTECHNOLOGY 2024; 35:125704. [PMID: 38055964 DOI: 10.1088/1361-6528/ad12e8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 12/05/2023] [Indexed: 12/08/2023]
Abstract
Transparent two-dimensional (2D) magnetic materials may bring intriguing features and are indispensable for transparent electronics. However, it is rare to find both optical transparency and room-temperature ferromagnetism simultaneously in a single 2D material. Herein, we explore the possibility of both these features in 2D WSe2/1T-VSe2(1ML)/WSe2and WSe2/1T-VSe2(2ML)/WSe2heterostructures by taking one monolayer (1ML) and two monolayers (2ML) of 1T-VSe2using first-principles calculations. Further, we investigate anomalous Hall conductivity (AHC) and anomalous Nernst conductivity (ANC) using a maximally localized Wannier function. The WSe2/1T-VSe2(1ML)/WSe2and WSe2/1T-VSe2(2ML)/WSe2systems show Curie temperatures of 328 and 405 K. Under biaxial compressive strain, the magnetic anisotropy of both systems is switched from in-plane to out-of-plane. We find a large AHC of 1.51 e2/h and 3.10 e2/h in the electron-doped region for strained WSe2/1T-VSe2(1ML)/WSe2and WSe2/1T-VSe2(2ML)/WSe2systems. Furthermore, we obtain a giant ANC of 3.94 AK-1m-1in a hole-doped strained WSe2/1T-VSe2(2ML)/WSe2system at 100 K. Both WSe2/1T-VSe2(1ML)/WSe2and WSe2/1T-VSe2(2ML)/WSe2are optically transparent in the visible ranges with large refractive indices of 3.2-3.4. Our results may suggest that the WSe2/1T-VSe2/WSe2structure possesses multifunctional physical properties and these features can be utilized for spintronics and optoelectronics device applications such as magnetic sensors, memory devices, and transparent magneto-optic devices at room temperature.
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Affiliation(s)
- Imran Khan
- Department of Physics, Pukyong National University, Busan 48513, Republic of Korea
| | - Brahim Marfoua
- Department of Physics, Pukyong National University, Busan 48513, Republic of Korea
| | - Jisang Hong
- Department of Physics, Pukyong National University, Busan 48513, Republic of Korea
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7
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Ochs AM, Fecher GH, He B, Schnelle W, Felser C, Heremans JP, Goldberger JE. Synergizing a Large Ordinary Nernst Effect and Axis-Dependent Conduction Polarity in Flat Band KMgBi Crystals. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2308151. [PMID: 37853575 DOI: 10.1002/adma.202308151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/10/2023] [Indexed: 10/20/2023]
Abstract
The exploration of quantum materials in which an applied thermo/electrical/magnetic field along one crystallographic direction produces an anisotropic response has led to unique functionalities. Along these lines, KMgBi is a layered, narrow gap semiconductor near a critical state between multiple Dirac phases due to the presence of a flat band near the Fermi level. The valence band is highly anisotropic with minimal cross-plane dispersion, which, in combination with an isotropic conduction band, enables axis-dependent conduction polarity. Thermopower and Hall measurements indicate dominant p-type conduction along the cross-plane direction, and n-type conduction along the in-plane direction, leading to a significant zero-field transverse thermoelectric response when the heat flux is at an angle to the principal crystallographic directions. Additionally, a large Ordinary Nernst effect (ONE) is observed with an applied field. It arises from the ambipolar term in the Nernst effect, whereby the Lorentz force on electrons and holes makes them drift in opposite directions so that the resulting Nernst voltage becomes a function of the difference between their partial thermopowers, greatly enhancing the ONE. It is proven that axis-dependent polarity can synergistically enhance the ONE, in addition to leading to a zero-field transverse thermoelectric performance.
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Affiliation(s)
- Andrew M Ochs
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Gerhard H Fecher
- Max-Planck Institute for the Chemical Physics of Solids, 01187, Dresden, Germany
| | - Bin He
- Max-Planck Institute for the Chemical Physics of Solids, 01187, Dresden, Germany
| | - Walter Schnelle
- Max-Planck Institute for the Chemical Physics of Solids, 01187, Dresden, Germany
| | - Claudia Felser
- Max-Planck Institute for the Chemical Physics of Solids, 01187, Dresden, Germany
| | - Joseph P Heremans
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, 43210, USA
- Department of Physics, The Ohio State University, Columbus, OH, 43210, USA
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Joshua E Goldberger
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
- Max-Planck Institute for the Chemical Physics of Solids, 01187, Dresden, Germany
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, 43210, USA
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8
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Guo X, Li X, Zhu Z, Behnia K. Onsager Reciprocal Relation between Anomalous Transverse Coefficients of an Anisotropic Antiferromagnet. PHYSICAL REVIEW LETTERS 2023; 131:246302. [PMID: 38181139 DOI: 10.1103/physrevlett.131.246302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/23/2023] [Accepted: 11/21/2023] [Indexed: 01/07/2024]
Abstract
Whenever two irreversible processes occur simultaneously, time-reversal symmetry of microscopic dynamics gives rise, on a macroscopic level, to Onsager's reciprocal relations, which impose constraints on the number of independent components of any transport coefficient tensor. Here, we show that in the antiferromagnetic YbMnBi_{2}, which displays a strong temperature-dependent anisotropy, Onsager's reciprocal relations are strictly satisfied for anomalous electric (σ_{ij}^{A}) and anomalous thermoelectric (α_{ij}^{A}) conductivity tensors. In contradiction with what was recently reported by Pan et al. [Nat. Mater. 21, 203 (2022)NMAACR1476-112210.1038/s41563-021-01149-2], we find that σ_{ij}^{A}(H)=σ_{ji}^{A}(-H) and α_{ij}^{A}(H)=α_{ji}^{A}(-H). This equality holds in the whole temperature window irrespective of the relative weights of the intrinsic or extrinsic mechanisms. The α_{ij}^{A}/σ_{ij}^{A} ratio is close to k_{B}/e at room temperature but peaks to an unprecedented magnitude of 2.9k_{B}/e at ∼150 K, which may involve nondegenerate carriers of small Fermi surface pockets.
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Affiliation(s)
- Xiaodong Guo
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiaokang Li
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zengwei Zhu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Kamran Behnia
- Laboratoire de Physique et Etude des Matériaux (CNRS/UPMC), Ecole Supérieure de Physique et de Chimie Industrielles, 10 Rue Vauquelin, 75005 Paris, France
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9
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Tanaka H, Higo T, Uesugi R, Yamagata K, Nakanishi Y, Machinaga H, Nakatsuji S. Roll-to-Roll Printing of Anomalous Nernst Thermopile for Direct Sensing of Perpendicular Heat Flux. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2303416. [PMID: 37343181 DOI: 10.1002/adma.202303416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/12/2023] [Indexed: 06/23/2023]
Abstract
The anomalous Nernst effect (ANE) converts heat flux perpendicular to the plane into electricity, in sharp contrast with the Seebeck effect (SE), enabling mass production, large area, and flexibility of their devices through ordinary thin-film fabrication techniques. Heat flux sensors, one of the most promising applications of ANE, are powerful devices for evaluating heat flow and can lead to energy savings through efficient thermal management. In reality, however, SE caused by the in-plane heat flux is always superimposed on the measurement signal, making it difficult to evaluate the perpendicular heat flux. Here, ANE-type heat flux sensors that selectively detect a perpendicular heat flux are fabricated by adjusting the net Seebeck coefficient in their thermopile circuit with mass-producible roll-to-roll sputtering methods. The direct sensing of perpendicular heat flux using ANE-based flexible thermopiles, as well as their simple fabrication process, paves the way for the practical application of thin-film thermoelectric devices.
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Affiliation(s)
- Hirokazu Tanaka
- Laboratory for Magnetic and Electronic Properties at Interface, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Core Technology Research Center, Nitto Denko Corporation, 1-1-2 Ibaraki, Osaka, 567-8680, Japan
| | - Tomoya Higo
- Laboratory for Magnetic and Electronic Properties at Interface, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Department of Physics, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwa, Chiba, 277-8581, Japan
| | - Ryota Uesugi
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwa, Chiba, 277-8581, Japan
| | - Kazuto Yamagata
- Laboratory for Magnetic and Electronic Properties at Interface, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Core Technology Research Center, Nitto Denko Corporation, 1-1-2 Ibaraki, Osaka, 567-8680, Japan
| | - Yosuke Nakanishi
- Laboratory for Magnetic and Electronic Properties at Interface, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Core Technology Research Center, Nitto Denko Corporation, 1-1-2 Ibaraki, Osaka, 567-8680, Japan
| | - Hironobu Machinaga
- Laboratory for Magnetic and Electronic Properties at Interface, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Core Technology Research Center, Nitto Denko Corporation, 1-1-2 Ibaraki, Osaka, 567-8680, Japan
| | - Satoru Nakatsuji
- Laboratory for Magnetic and Electronic Properties at Interface, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Department of Physics, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwa, Chiba, 277-8581, Japan
- Trans-scale Quantum Science Institute, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
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10
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Fyhn EH, Brataas A, Qaiumzadeh A, Linder J. Superconducting Proximity Effect and Long-Ranged Triplets in Dirty Metallic Antiferromagnets. PHYSICAL REVIEW LETTERS 2023; 131:076001. [PMID: 37656842 DOI: 10.1103/physrevlett.131.076001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 05/19/2023] [Accepted: 07/19/2023] [Indexed: 09/03/2023]
Abstract
Antiferromagnets have no net spin splitting on the scale of the superconducting coherence length. Despite this, antiferromagnets have been observed to suppress superconductivity in a similar way as ferromagnets, a phenomenon that still lacks a clear understanding. We find that this effect can be explained by the role of impurities in antiferromagnets. Using quasiclassical Green's functions, we study the proximity effect and critical temperature in diffusive superconductor-metallic antiferromagnet bilayers. The nonmagnetic impurities acquire an effective magnetic component in the antiferromagnet. This not only reduces the critical temperature but also separates the superconducting correlations into short-ranged and long-ranged components, similar to ferromagnetic proximity systems.
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Affiliation(s)
- Eirik Holm Fyhn
- Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Arne Brataas
- Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Alireza Qaiumzadeh
- Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Jacob Linder
- Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
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11
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Li M, Pi H, Zhao Y, Lin T, Zhang Q, Hu X, Xiong C, Qiu Z, Wang L, Zhang Y, Cai J, Liu W, Sun J, Hu F, Gu L, Weng H, Wu Q, Wang S, Chen Y, Shen B. Large Anomalous Nernst Effects at Room Temperature in Fe 3 Pt Thin Films. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2301339. [PMID: 37308132 DOI: 10.1002/adma.202301339] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 06/04/2023] [Indexed: 06/14/2023]
Abstract
Heat current in ferromagnets can generate a transverse electric voltage perpendicular to magnetization, known as anomalous Nernst effect (ANE). ANE originates intrinsically from the combination of large Berry curvature and density of states near the Fermi energy. It shows technical advantages over the conventional longitudinal Seebeck effect in converting waste heat to electricity due to its unique transverse geometry. However, materials showing giant ANE remain to be explored. Herein, a large ANE thermopower of Syx ≈ 2 µV K-1 at room temperature in ferromagnetic Fe3 Pt epitaxial films is reported, which also show a giant transverse thermoelectric conductivity of αyx ≈ 4 A K-1 m-1 and a remarkable coercive field of 1300 Oe. The theoretical analysis reveals that the strong spin-orbit interaction in addition to the hybridization between Pt 5d and Fe 3d electrons leads to a series of distinct energy gaps and large Berry curvature in the Brillouin zone, which is the key for the large ANE. These results highlight the important roles of both Berry curvature and spin-orbit coupling in achieving large ANE at zero magnetic field, providing pathways to explore materials with giant transverse thermoelectric effect without an external magnetic field.
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Affiliation(s)
- Minghang Li
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hanqi Pi
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yunchi Zhao
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Ting Lin
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qinghua Zhang
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xinzhe Hu
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Changmin Xiong
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Zhiyong Qiu
- School of Material Science and Engineering, Dalian University of Technology, Dalian, 116024, China
| | - Lichen Wang
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
| | - Ying Zhang
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jianwang Cai
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wuming Liu
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jirong Sun
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fengxia Hu
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lin Gu
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Hongming Weng
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Quansheng Wu
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shouguo Wang
- School of Materials Science and Engineering, Anhui University, Hefei, 230601, China
| | - Yunzhong Chen
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Baogen Shen
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou, 341000, China
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12
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Kim JM, Kim SJ, Kang MG, Choi JG, Lee S, Park J, Van Phuoc C, Kim KW, Kim KJ, Jeong JR, Lee KJ, Park BG. Enhanced spin Seebeck effect via oxygen manipulation. Nat Commun 2023; 14:3365. [PMID: 37291127 PMCID: PMC10250387 DOI: 10.1038/s41467-023-39116-x] [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: 10/26/2022] [Accepted: 05/30/2023] [Indexed: 06/10/2023] Open
Abstract
Spin Seebeck effect (SSE) refers to the generation of an electric voltage transverse to a temperature gradient via a magnon current. SSE offers the potential for efficient thermoelectric devices because the transverse geometry of SSE enables to utilize waste heat from a large-area source by greatly simplifying the device structure. However, SSE suffers from a low thermoelectric conversion efficiency that must be improved for widespread application. Here we show that the SSE substantially enhances by oxidizing a ferromagnet in normal metal/ferromagnet/oxide structures. In W/CoFeB/AlOx structures, voltage-induced interfacial oxidation of CoFeB modifies the SSE, resulting in the enhancement of thermoelectric signal by an order of magnitude. We describe a mechanism for the enhancement that results from a reduced exchange interaction of the oxidized region of ferromagnet, which in turn increases a temperature difference between magnons in the ferromagnet and electrons in the normal metal and/or a gradient of magnon chemical potential in the ferromagnet. Our result will invigorate research for thermoelectric conversion by suggesting a promising way of improving the SSE efficiency.
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Affiliation(s)
- Jeong-Mok Kim
- Department of Materials Science and Engineering, KAIST, Daejeon, 34141, Korea
| | - Seok-Jong Kim
- Department of Materials Science and Engineering, KAIST, Daejeon, 34141, Korea
- Department of Physics, KAIST, Daejeon, 34141, Korea
| | - Min-Gu Kang
- Department of Materials Science and Engineering, KAIST, Daejeon, 34141, Korea
- Department of Materials, ETH Zurich, Zurich, Switzerland
| | - Jong-Guk Choi
- Department of Materials Science and Engineering, KAIST, Daejeon, 34141, Korea
| | - Soogil Lee
- Department of Materials Science and Engineering, KAIST, Daejeon, 34141, Korea
| | | | - Cao Van Phuoc
- Department of Materials Science and Engineering, Chungnam National University, Daejeon, 34134, Korea
| | - Kyoung-Whan Kim
- Center for Spintronics, Korea Institute of Science and Technology, Seoul, 02792, Korea
| | - Kab-Jin Kim
- Department of Physics, KAIST, Daejeon, 34141, Korea
| | - Jong-Ryul Jeong
- Department of Materials Science and Engineering, Chungnam National University, Daejeon, 34134, Korea
| | - Kyung-Jin Lee
- Department of Physics, KAIST, Daejeon, 34141, Korea.
| | - Byong-Guk Park
- Department of Materials Science and Engineering, KAIST, Daejeon, 34141, Korea.
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13
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Roychowdhury S, Yao M, Samanta K, Bae S, Chen D, Ju S, Raghavan A, Kumar N, Constantinou P, Guin SN, Plumb NC, Romanelli M, Borrmann H, Vergniory MG, Strocov VN, Madhavan V, Shekhar C, Felser C. Anomalous Hall Conductivity and Nernst Effect of the Ideal Weyl Semimetallic Ferromagnet EuCd 2 As 2. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207121. [PMID: 36828783 PMCID: PMC10161038 DOI: 10.1002/advs.202207121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/22/2023] [Indexed: 05/06/2023]
Abstract
Weyl semimetal is a unique topological phase with topologically protected band crossings in the bulk and robust surface states called Fermi arcs. Weyl nodes always appear in pairs with opposite chiralities, and they need to have either time-reversal or inversion symmetry broken. When the time-reversal symmetry is broken the minimum number of Weyl points (WPs) is two. If these WPs are located at the Fermi level, they form an ideal Weyl semimetal (WSM). In this study, intrinsic ferromagnetic (FM) EuCd2 As2 are grown, predicted to be an ideal WSM and studied its electronic structure by angle-resolved photoemission spectroscopy, and scanning tunneling microscopy which agrees closely with the first principles calculations. Moreover, anomalous Hall conductivity and Nernst effect are observed, resulting from the non-zero Berry curvature, and the topological Hall effect arising from changes in the band structure caused by spin canting produced by magnetic fields. These findings can help realize several exotic quantum phenomena in inorganic topological materials that are otherwise difficult to assess because of the presence of multiple pairs of Weyl nodes.
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Affiliation(s)
| | - Mengyu Yao
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Kartik Samanta
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Seokjin Bae
- Department of Physics and Materials Research Laboratory, University of Illinois Urbana, Champaign, Urbana, IL, 61801, USA
| | - Dong Chen
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Sailong Ju
- Swiss Light Source, Paul Scherrer Institute, Villigen-PSI, CH-5232, Switzerland
| | - Arjun Raghavan
- Department of Physics and Materials Research Laboratory, University of Illinois Urbana, Champaign, Urbana, IL, 61801, USA
| | - Nitesh Kumar
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
- S. N. Bose National Centre for Basic Sciences, Salt Lake City, Kolkata, 700 106, India
| | | | - Satya N Guin
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
- Department of Chemistry, Birla Institute of Technology and Science, Pilani - Hyderabad Campus, Hyderabad, 500078, India
| | | | - Marisa Romanelli
- Department of Physics and Materials Research Laboratory, University of Illinois Urbana, Champaign, Urbana, IL, 61801, USA
| | - Horst Borrmann
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Maia G Vergniory
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
- Donostia International Physics Center, Donostia-San Sebastian, 20018, Spain
| | - Vladimir N Strocov
- Swiss Light Source, Paul Scherrer Institute, Villigen-PSI, CH-5232, Switzerland
| | - Vidya Madhavan
- Department of Physics and Materials Research Laboratory, University of Illinois Urbana, Champaign, Urbana, IL, 61801, USA
| | - Chandra Shekhar
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
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14
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Wang H, Zhou Z, Ying J, Xiang Z, Wang R, Wang A, Chai Y, He M, Lu X, Han G, Pan Y, Wang G, Zhou X, Chen X. Large Magneto-Transverse and Longitudinal Thermoelectric Effects in the Magnetic Weyl Semimetal TbPtBi. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2206941. [PMID: 36300801 DOI: 10.1002/adma.202206941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Magnetic topological semimetals provide new opportunities for power generation and solid-state cooling based on thermoelectric (TE) effect. The interplay between magnetism and nontrivial band topology prompts the magnetic topological semimetals to yield strong transverse TE effect, while the longitudinal TE performance is usually poor. Herein, it is demonstrated that the magnetic Weyl semimetal TbPtBi has high value for both transverse and longitudinal thermopower with large power factor (PF). At 300 K and 13.5 Tesla, the transverse thermopower and PF reach up to 214 µV K-1 and 35 µW cm-1 K-2 , respectively, which are comparable to those of state-of-the-art TE materials. Combining first-principles calculations, longitudinal magnetoresistance and planar Hall resistance measurements, and two-band model fitting, the large transverse thermopower and PF are attributed to both bipolar effect and large Hall angle. Moreover, the imperfectly compensated charge carriers and large transverse magnetoresistance induce the maximum magneto-longitudinal thermopower of 251 µV K-1 with a PF of 24 µW cm-1 K-2 at 150 K and 13.5 Tesla, which is two times higher than that at zero magnetic field. This work demonstrates the great potential of topological semimetals for TEs and offers a new excellent candidate for magneto-TEs.
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Affiliation(s)
- Honghui Wang
- College of Physics and Center of Quantum Materials & Devices, Chongqing University, Chongqing, 401331, P. R. China
| | - Zizhen Zhou
- College of Physics and Center of Quantum Materials & Devices, Chongqing University, Chongqing, 401331, P. R. China
| | - Jianjun Ying
- CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
| | - Ziji Xiang
- CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
| | - Rui Wang
- College of Physics and Center of Quantum Materials & Devices, Chongqing University, Chongqing, 401331, P. R. China
| | - Aifeng Wang
- College of Physics and Center of Quantum Materials & Devices, Chongqing University, Chongqing, 401331, P. R. China
| | - Yisheng Chai
- College of Physics and Center of Quantum Materials & Devices, Chongqing University, Chongqing, 401331, P. R. China
| | - Mingquan He
- College of Physics and Center of Quantum Materials & Devices, Chongqing University, Chongqing, 401331, P. R. China
| | - Xu Lu
- College of Physics and Center of Quantum Materials & Devices, Chongqing University, Chongqing, 401331, P. R. China
| | - Guang Han
- College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, P. R. China
| | - Yu Pan
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Guoyu Wang
- College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, P. R. China
| | - Xiaoyuan Zhou
- College of Physics and Center of Quantum Materials & Devices, Chongqing University, Chongqing, 401331, P. R. China
- Analytical and Testing Center, Chongqing University, Chongqing, 401331, P. R. China
| | - Xianhui Chen
- CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
- High Magnetic Field Laboratory of the Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, P. R. China
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15
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Modak R, Sakuraba Y, Hirai T, Yagi T, Sepehri-Amin H, Zhou W, Masuda H, Seki T, Takanashi K, Ohkubo T, Uchida KI. Sm-Co-based amorphous alloy films for zero-field operation of transverse thermoelectric generation. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2022; 23:767-782. [PMID: 36386550 PMCID: PMC9662036 DOI: 10.1080/14686996.2022.2138538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 10/05/2022] [Accepted: 10/17/2022] [Indexed: 06/15/2023]
Abstract
Transverse thermoelectric generation using magnetic materials is essential to develop active thermal engineering technologies, for which the improvements of not only the thermoelectric output but also applicability and versatility are required. In this study, using combinatorial material science and lock-in thermography technique, we have systematically investigated the transverse thermoelectric performance of Sm-Co-based alloy films. The high-throughput material investigation revealed the best Sm-Co-based alloys with the large anomalous Nernst effect (ANE) as well as the anomalous Ettingshausen effect (AEE). In addition to ANE/AEE, we discovered unique and superior material properties in these alloys: the amorphous structure, low thermal conductivity, and large in-plane coercivity and remanent magnetization. These properties make it advantageous over conventional materials to realize heat flux sensing applications based on ANE, as our Sm-Co-based films can generate thermoelectric output without an external magnetic field. Importantly, the amorphous nature enables the fabrication of these films on various substrates including flexible sheets, making the large-scale and low-cost manufacturing easier. Our demonstration will provide a pathway to develop flexible transverse thermoelectric devices for smart thermal management.
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Affiliation(s)
- Rajkumar Modak
- Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Yuya Sakuraba
- Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takamasa Hirai
- Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Yagi
- National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | - Hossein Sepehri-Amin
- Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Weinan Zhou
- Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Hiroto Masuda
- Institute for Materials Research, Tohoku University, Sendai, Japan
| | - Takeshi Seki
- Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, Tsukuba, Japan
- Institute for Materials Research, Tohoku University, Sendai, Japan
- Center for Spintronics Research Network, Tohoku University, Sendai, Japan
| | - Koki Takanashi
- Institute for Materials Research, Tohoku University, Sendai, Japan
- Center for Spintronics Research Network, Tohoku University, Sendai, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai, Japan
| | - Tadakatsu Ohkubo
- Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Ken-ichi Uchida
- Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, Tsukuba, Japan
- Institute for Materials Research, Tohoku University, Sendai, Japan
- Center for Spintronics Research Network, Tohoku University, Sendai, Japan
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16
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Roychowdhury S, Ochs AM, Guin SN, Samanta K, Noky J, Shekhar C, Vergniory MG, Goldberger JE, Felser C. Large Room Temperature Anomalous Transverse Thermoelectric Effect in Kagome Antiferromagnet YMn 6 Sn 6. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2201350. [PMID: 35980946 DOI: 10.1002/adma.202201350] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 08/03/2022] [Indexed: 06/15/2023]
Abstract
Kagome magnets possess several novel nontrivial topological features owing to the strong correlation between topology and magnetism that extends to their applications in the field of thermoelectricity. Conventional thermoelectric (TE) devices use the Seebeck effect to convert heat into electrical energy. In contrast, transverse thermoelectric devices based on the Nernst effect are attracting recent attention due to their unique transverse geometry, which uses a single material to eliminate the need for a multitude of electrical connections compared to conventional TE devices. Here, a large anomalous transverse thermoelectric effect of ≈2 µV K-1 at room temperature in a kagome antiferromagnet YMn6 Sn6 single crystal is obtained. The obtained value is larger than that of state-of-the-art canted antiferromagnetic (AFM) materials and comparable with ferromagnetic systems. The large anomalous Nernst effect (ANE) can be attributed to the net Berry curvature near the Fermi level. Furthermore, the ANE of the AFM YMn6 Sn6 exceeds the magnetization scaling relationship of conventional ferromagnets. The results clearly illustrate that AFM material YMn6 Sn6 is an ideal topological material for room-temperature transverse thermoelectric applications.
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Affiliation(s)
| | | | - Satya N Guin
- Department of Chemistry, Birla Institute of Technology and Science, Pilani - Hyderabad Campus, Hyderabad, 500078, India
| | - Kartik Samanta
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Jonathan Noky
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Chandra Shekhar
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Maia G Vergniory
- Donostia International Physics Center, Donostia-San Sebastian, 20018, Spain
| | | | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
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17
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Lopez-Polin G, Aramberri H, Marques-Marchan J, Weintrub BI, Bolotin KI, Cerdá JI, Asenjo A. High-Power-Density Energy-Harvesting Devices Based on the Anomalous Nernst Effect of Co/Pt Magnetic Multilayers. ACS APPLIED ENERGY MATERIALS 2022; 5:11835-11843. [PMID: 36185812 PMCID: PMC9516660 DOI: 10.1021/acsaem.2c02422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 08/18/2022] [Indexed: 06/16/2023]
Abstract
The anomalous Nernst effect (ANE) is a thermomagnetic phenomenon with potential applications in thermal energy harvesting. While many recent works studied the approaches to increase the ANE coefficient of materials, relatively little effort was devoted to increasing the power supplied by the effect. Here, we demonstrate a nanofabricated device with record power density generated by the ANE. To accomplish this, we fabricate micrometer-sized devices in which the thermal gradient is 3 orders of magnitude higher than conventional macroscopic devices. In addition, we use Co/Pt multilayers, a system characterized by a high ANE thermopower (∼1 μV/K), low electrical resistivity, and perpendicular magnetic anisotropy. These innovations allow us to obtain power densities of around 13 ± 2 W/cm3. We believe that this design may find uses in harvesting wasted energy, e.g., in electronic devices.
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Affiliation(s)
| | - Hugo Aramberri
- Materials
Research and Technology Department, Luxembourg
Institute of Science and Technology (LIST), L-4362 Esch-sur-Alzette, Luxembourg
| | | | | | - Kirill I. Bolotin
- Department
of Physics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Jorge I. Cerdá
- Instituto
de Ciencia de Materiales de Madrid (ICMM-CSIC), 28049 Madrid, Spain
| | - Agustina Asenjo
- Instituto
de Ciencia de Materiales de Madrid (ICMM-CSIC), 28049 Madrid, Spain
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18
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Ultrahigh transverse thermoelectric power factor in flexible Weyl semimetal WTe 2. Nat Commun 2022; 13:3909. [PMID: 35798731 PMCID: PMC9262886 DOI: 10.1038/s41467-022-31372-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 06/16/2022] [Indexed: 11/19/2022] Open
Abstract
Topological semimetals are well known for their interesting physical properties, while their mechanical properties have rarely received attention. With the increasing demand for flexible electronics, we explore the great potential of the van der Waals bonded Weyl semimetal WTe2 for flexible thermoelectric applications. We find that WTe2 single crystals have an ultrahigh Nernst power factor of ~3 Wm−1K−2, which outperforms the conventional Seebeck power factors of the state-of-the-art thermoelectric semiconductors by 2–3 orders of magnitude. A unique band structure that hosts compensated electrons and holes with extremely high mobilities is the primary mechanism for this huge Nernst power factor. Moreover, a large Ettingshausen signal of ~5 × 10−5 KA−1m is observed at 23.1 K and 9 T. In this work, the combination of the exceptional Nernst–Ettingshausen performance and excellent mechanical transformative ability of WTe2 would be instructive for flexible micro-/nano-thermoelectric devices. Flexible thermoelectrics are of great interest with increasing demand of flexible and wearable electronics. Here, the authors demonstrate that the Weyl semimetal, WTe2, has a high Nernst power factor and great mechanical flexibility.
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19
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Yang Y, Fu Y, Zhu W, He J, Liu B, Liu C, Li L, Niu C, Luo Y. Single crystal growth and physical properties of layered compound SrCdBi 2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:315701. [PMID: 35588724 DOI: 10.1088/1361-648x/ac718d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
We have grown the high quality single crystals of SrCdBi2successfully and investigated the physical properties systematically through measurements of magnetoresistance (MR), Hall effect, magnetic susceptibility, and specific heat measurements. The compound is a nonmagnetic 112-type pnictide with a Bi square net layer, which is potential for hosting Dirac fermions. We found that it exhibited metallic behavior with an anomaly appearing at around 210 K. MR study reveal that the electronic structure of SrCdBi2is quasi-two-dimensional. At low temperatures, we observed magnetic field induced metal-to-insulator-like transition and resistivity plateau, nonsaturating quasilinear MR, and high carrier mobility in magnetotransport measurements, which indicate the possible existence of nearly massless Dirac fermions in SrCdBi2. The anomaly at around 210 K can be observed in resistivity, Hall effect, and magnetic susceptibility, but cannot be detected in heat capacity. This implies the anomaly might be caused by domain formation or disorder. We found that the nonsaturating linear MR in SrCdBi2is likely caused by both of the quantum linear dispersion and the classical disorder. Our findings suggest that SrCdBi2is a natural experimental platform for realizing the topological properties of nonmagnetic 112-type pnictides.
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Affiliation(s)
- Yi Yang
- School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, 450001, People's Republic of China
| | - Yu Fu
- College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang, 473061, People's Republic of China
| | - Wenliang Zhu
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an, 710062, People's Republic of China
| | - Junbao He
- College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang, 473061, People's Republic of China
| | - Bo Liu
- College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang, 473061, People's Republic of China
| | - Congbin Liu
- College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang, 473061, People's Republic of China
| | - Liang Li
- College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang, 473061, People's Republic of China
| | - Chunyao Niu
- School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, 450001, People's Republic of China
| | - Yongsong Luo
- College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang, 473061, People's Republic of China
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Uchida KI. Anisotropy boosts transverse thermoelectrics. NATURE MATERIALS 2022; 21:136-137. [PMID: 35110741 DOI: 10.1038/s41563-021-01160-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
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