Ta thickness effect on field-free switching and spin-orbit torque efficiency in a ferromagnetically coupled Co/Ta/CoFeB trilayer  

作　　者：冯重舒 于长秋 黄海侠 樊浩东 卫鸣璋 吴必瑞 金蒙豪 庄燕山 邵子霁 李海 温嘉红 张鉴 张雪峰 王宁宁 穆赛 周铁军 Zhongshu Feng;Changqiu Yu;Haixia Huang;Haodong Fan;Mingzhang Wei;Birui Wu;Menghao Jin;Yanshan Zhuang;Ziji Shao;Hai Li;Jiahong Wen;Jian Zhang;Xuefeng Zhang;Ningning Wang;Sai Mu;Tiejun Zhou(School of Electronics and Information Engineering,Hangzhou Dianzi University,Hangzhou 310018,China;Second Affiliation Institute of Advanced Magnetic Materials,College of Materials and Environmental Engineering,H)

机构地区：[1]School of Electronics and Information Engineering,Hangzhou Dianzi University,Hangzhou 310018,China [2]Second Affiliation Institute of Advanced Magnetic Materials,College of Materials and Environmental Engineering,Hangzhou Dianzi University,Hangzhou 310018,China angzhou Dianzi University,Hangzhou 310018,China

出　　处：《Chinese Physics B》2023年第4期719-723,共5页中国物理B（英文版）

基　　金：Project supported by the‘Pioneer’and‘Leading Goose’Research and Development Program of Zhejiang Province,China(Grant No.2022C01053);the National Natural Science Foundation of China(Grant Nos.11874135,12104119;12004090);Key Research and Development Program of Zhejiang Province,China(Grant No.2021C01039);Natural Science Foundation of Zhejiang Province,China(Grant Nos.LQ20F040005 and LQ21A050001)。

摘　　要：Current induced spin-orbit torque(SOT)switching of magnetization is a promising technology for nonvolatile spintronic memory and logic applications.In this work,we systematically investigated the effect of Ta thickness on the magnetic properties,field-free switching and SOT efficiency in a ferromagnetically coupled Co/Ta/Co Fe B trilayer with perpendicular magnetic anisotropy.We found that both the anisotropy field and coercivity increase with increasing Ta thickness from0.15 nm to 0.4 nm.With further increase of Ta thickness to 0.5 nm,two-step switching is observed,indicating that the two magnetic layers are magnetically decoupled.Measurements of pulse-current induced magnetization switching and harmonic Hall voltages show that the critical switching current density increases while the field-free switching ratio and SOT efficiency decrease with increasing Ta thickness.Both the enhanced spin memory loss and reduced interlayer exchange coupling might be responsible for theβ_(DL)decrease as the Ta spacer thickness increases.The studied structure with the incorporation of a Co Fe B layer is able to realize field-free switching in the strong ferromagnetic coupling region,which may contribute to the further development of magnetic tunnel junctions for better memory applications.

关 键 词：spin-orbit coupling interlayer exchange-coupling field-free switching 

分 类 号：O469[理学—凝聚态物理]