Perpendicular magnetization switching by large spin–orbit torques from sputtered Bi2Te3
Zheng Zhenyi1, 2, 3, Zhang Yue1, †, Zhu Daoqian1, Zhang Kun1, Feng Xueqiang1, He Yu1, Chen Lei1, Zhang Zhizhong1, 2, Liu Dijun2, Zhang Youguang1, 2, Amiri Pedram Khalili3, Zhao Weisheng1, ‡
       

(a) Thickness-dependent resistivity change measured by four-point method in MgO/Bi2Te3/MgO trilayers. Inset is an AFM image of Bi2Te3 (8 nm) sample. (b) Stack schematic of the investigated Bi2Te3/CoTb heterostructure. (c) Dependence of the magnetization direction of CoTb layer on x. When x is in the range of 6–8 nm, CoTb layers show excellent PMA properties.