1
|
Zhang Z, Guo Z, Lin J, Sun F, Han X, Wang G, Yuan W. Effect of Cu Doping on Structure and Physical Properties in the Antiferromagnetic Dirac Semimetal CaMnBi 2. Inorg Chem 2022; 61:4592-4597. [PMID: 35271274 DOI: 10.1021/acs.inorgchem.1c03410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The newly discovered AMnBi2 (A = Ca, Sr, Ba, Eu, and Yb) materials composed of two-dimensional Bi square nets provide an excellent platform to investigate the effect of magnetism on topological band structures. Effectively tuning the magnetic interaction in AMnBi2 is of great importance to advance this issue. Here, we describe an effective route to tune the magnetism in Dirac semimetal CaMnBi2 through Cu doping. Structural analysis on CaMn1-xCuxBi2 single crystals indicates that Cu atoms occupy the Mn sites randomly, with the maximum doping level of 25%. After Cu doping, the Bi square net in charge of the Dirac band is still retained, but the Bi-Bi bond distance is markedly shortened. The antiferromagnetic interaction of CaMnBi2 is strongly weakened in the Cu-doped crystals, with the transition temperature decreased from 260 to 85 K. On the contrary, the ferromagnetic component that originated from the canted AFM is enhanced, suggesting that the spin canting in this system is tunable. In addition, the magnetoresistance is decreased upon Cu doping, probably due to the disorder in structure. Our work suggests that the CaMn1-xCuxBi2 (0 ≤ x ≤ 0.25) system can offer a suitable playground to address the interplay between magnetism and the topological state.
Collapse
Affiliation(s)
- Zijing Zhang
- Department of Chemistry, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Zhongnan Guo
- Department of Chemistry, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Jiawei Lin
- Department of Chemistry, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Fan Sun
- Department of Chemistry, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Xue Han
- Department of Chemistry, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Gang Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China.,Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Wenxia Yuan
- Department of Chemistry, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| |
Collapse
|
2
|
Pan Y, Le C, He B, Watzman SJ, Yao M, Gooth J, Heremans JP, Sun Y, Felser C. Giant anomalous Nernst signal in the antiferromagnet YbMnBi 2. NATURE MATERIALS 2022; 21:203-209. [PMID: 34811495 PMCID: PMC8810386 DOI: 10.1038/s41563-021-01149-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 10/04/2021] [Indexed: 05/22/2023]
Abstract
A large anomalous Nernst effect (ANE) is crucial for thermoelectric energy conversion applications because the associated unique transverse geometry facilitates module fabrication. Topological ferromagnets with large Berry curvatures show large ANEs; however, they face drawbacks such as strong magnetic disturbances and low mobility due to high magnetization. Herein, we demonstrate that YbMnBi2, a canted antiferromagnet, has a large ANE conductivity of ~10 A m-1 K-1 that surpasses large values observed in other ferromagnets (3-5 A m-1 K-1). The canted spin structure of Mn guarantees a non-zero Berry curvature, but generates only a weak magnetization three orders of magnitude lower than that of general ferromagnets. The heavy Bi with a large spin-orbit coupling enables a large ANE and low thermal conductivity, whereas its highly dispersive px/y orbitals ensure low resistivity. The high anomalous transverse thermoelectric performance and extremely small magnetization make YbMnBi2 an excellent candidate for transverse thermoelectrics.
Collapse
Affiliation(s)
- Yu Pan
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.
| | - Congcong Le
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Bin He
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Sarah J Watzman
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, USA
- Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Mengyu Yao
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Johannes Gooth
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Joseph P Heremans
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, USA
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, USA
- Department of Physics, The Ohio State University, Columbus, OH, USA
| | - Yan Sun
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.
| |
Collapse
|