Field-induced Néel vector bi-reorientation of a ferrimagnetic insulator in the vicinity of compensation temperature  

作　　者：Peng Wang Hui Zhao Zhongzhi Luan Siyu Xia Tao Feng Lifan Zhou 王鹏;赵辉;栾仲智;夏思宇;丰韬;周礼繁(College of Mathematics and Physics,Qingdao University of Science and Technology,Qingdao 266061,China;National Laboratory of Solid State Microstructures,Jiangsu Provincial Key Laboratory for Nanotechnology and Department of Physics,Nanjing University,Nanjing 210093,China)

机构地区：[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

出　　处：《Chinese Physics B》2021年第2期481-486,共6页中国物理B（英文版）

基　　金：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);the Fundamental Research Funds for the Central Universities,China(Grant No.020414380121)。

摘　　要：The spin Hall magnetoresistance(SMR)effect in Pt/Gd_(3)Fe_(5)O_(12)(Gd IG)bilayers was systematically investigated.The sign of SMR changes twice with increasing magnetic field in the vicinity of the magnetization compensation point(TM)of Gd IG.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 TM.As a result,the Néel vector aligns with the field after the spin-flop transition,meaning that a bi-reorientation of the Néel vector is produced.Theoretical calculations based on the Néel’s theory and SMR theory also support our conclusions.Our findings indicate that the Néel-vector direction of a ferrimagnet can be tuned across a wide range by a relatively low external field around TM.

关 键 词：spin Hall magnetoresistance FERRIMAGNETS magnetic insulators magnetization switching 

分 类 号：O469[理学—凝聚态物理]