中国物理B ›› 2021, Vol. 30 ›› Issue (2): 27501-0.doi: 10.1088/1674-1056/abbbef

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  • 收稿日期:2020-07-25 修回日期:2020-09-05 接受日期:2020-09-28 出版日期:2021-01-18 发布日期:2021-01-26

Field-induced N\'eel vector bi-reorientation of a ferrimagnetic insulator in the vicinity of compensation temperature

Peng Wang(王鹏)1,†, Hui Zhao(赵辉)2, Zhongzhi Luan(栾仲智)2, Siyu Xia(夏思宇)2, Tao Feng(丰韬)2, and Lifan Zhou(周礼繁)2,‡   

  1. 1 College of Mathematics and Physics, Qingdao University of Science and Technology, Qingdao 266061, China; 2 National Laboratory of Solid State Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology and Department of Physics, Nanjing University, Nanjing 210093, China
  • Received:2020-07-25 Revised:2020-09-05 Accepted:2020-09-28 Online:2021-01-18 Published:2021-01-26
  • Contact: Corresponding author. E-mail: pwang7000@163.com Corresponding author. E-mail: lifan-zhou@foxmail.com
  • Supported by:
    Project supported by the National Key Research and Development Program of China (Grant Nos. 2017YFA0303202 and 2016YFA0300803), the National Natural Science Foundation of China (Grant Nos. 11904194, 11727808, and 11674159), and the Fundamental Research Funds for the Central Universities, China (Grant No. 020414380121).

Abstract: The spin Hall magnetoresistance (SMR) effect in Pt/Gd3Fe5O12 (GdIG) bilayers was systematically investigated. The sign of SMR changes twice with increasing magnetic field in the vicinity of the magnetization compensation point (T M) of GdIG. However, conventional SMR theory predicts the invariant SMR sign in the heterostructure composed of a heavy metal film in contact with a ferromagnetic or antiferromagnetic film. We conclude that this is because of the significant enhancement of the magnetic moment of the Gd sub-lattice and the unchanged moment of the Fe sub-lattice with a relatively large field, meaning that a small net magnetic moment is induced at T M. As a result, the N\'eel vector aligns with the field after the spin-flop transition, meaning that a bi-reorientation of the N\'eel vector is produced. Theoretical calculations based on the N\'eel's theory and SMR theory also support our conclusions. Our findings indicate that the N\'eel-vector direction of a ferrimagnet can be tuned across a wide range by a relatively low external field around T M.

Key words: spin Hall magnetoresistance, ferrimagnets, magnetic insulators, magnetization switching

中图分类号:  (Magnetotransport phenomena; materials for magnetotransport)

  • 75.47.-m
75.50.Gg (Ferrimagnetics) 75.60.Jk (Magnetization reversal mechanisms)