Field-Free Spin-Orbit Torque Switching of Perpendicular Magnetization by the Rashba Interface

被引：56

作者：

Cui, Baoshan ^{[1
,2
,3
]}

Wu, Hao ^{[1
]}

Li, Dong ^{[4
]}

Razavi, Seyed Armin ^{[1
]}

Wu, Di ^{[1
]}

Wong, Kin L. ^{[1
]}

Chang, Meixia ^{[2
,3
]}

Gao, Meizhen ^{[2
,3
]}

Zuo, Yalu ^{[2
,3
]}

Xi, Li ^{[2
,3
]}

Wang, Kang L. ^{[1
]}

机构：

[1] Univ Calif Los Angeles, Dept Elect & Comp Engn, Los Angeles, CA 90095 USA

[2] Lanzhou Univ, Minist Educ, Key Lab Magnetism & Magnet Mat, Lanzhou 730000, Gansu, Peoples R China

[3] Lanzhou Univ, Sch Phys Sci & Technol, Lanzhou 730000, Gansu, Peoples R China

[4] Shanxi Normal Univ, Res Inst Mat Sci, Linfen 041004, Shanxi, Peoples R China

来源：

ACS APPLIED MATERIALS & INTERFACES | 2019年 / 11卷 / 42期

基金：

美国国家科学基金会; 中国国家自然科学基金;

关键词：

spin-orbit torque; perpendicular magnetic anisotropy; interfacial decoration; field-free magnetization switching; Rashba effect; interfacial oxygen content;

D O I：

10.1021/acsami.9b13622

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Current-induced spin-orbit torques (SOTs) enable efficient electrical manipulation of the magnetization in heterostructures with a perpendicular magnetic anisotropy through the Rashba effect or spin-Hall effect. However, in conventional SOT-based heterostructures, an in-plane bias magnetic field along the current direction is required for the deterministic switching. Here, we report that the field-free SOT switching can be achieved by introducing a wedged oxide interface between a heavy metal and a ferromagnet. The results demonstrate that the field-free SOT switching is determined by a current-induced perpendicular effective field (H-z(eff)) originating from the interfacial Rashba effect due to the lateral structural symmetry-breaking introduced by the wedged oxide layer. Furthermore, we show that the sign and magnitude of H-z(eff) exhibit a significant dependence on the interfacial oxygen content, which can be controlled by the inserted oxide thickness. Our findings provide a deeper insight into the field-free SOT switching by the interfacial Rashba effect.

引用

页码：39369 / 39375

页数：7