Bulk Spin Torque-Driven Perpendicular Magnetization Switching in L10 FePt Single Layer
Bulk Spin Torque-Driven Perpendicular Magnetization Switching in L10 FePt Single Layer
复制标题
L1(0)FePt 单层体自旋扭矩驱动垂直磁化开关
DOI：
10.1002/adma.202002607
复制
发表时间：
2020-06-28
影响因子：
29.4
通讯作者：
Qiu, Xuepeng
中科院分区：
文献类型：
--
作者：
Tang, Meng;Shen, Ka;Qiu, Xuepeng
Due to its inherent superior perpendicular magnetocrystalline anisotropy, the FePt inL1(0)phase enables magnetic storage and memory devices with ultrahigh capacity. However, reversing the FePt magnetic state, and therefore encoding information, has proven to be extremely difficult. Here, it is demonstrated that an electric current can exert a large spin torque on anL1(0)FePt magnet, ultimately leading to reversible magnetization switching. The spin torque monotonically increases with increasing FePt thickness, exhibiting a bulk characteristic. Meanwhile, the spin torque effective fields and switching efficiency increase as the FePt approaches higher chemical ordering with stronger spin-orbit coupling. The symmetry breaking that generates spin torque withinL1(0)FePt is shown to arise from an inherent structural gradient along the film normal direction. By artificially reversing the structural gradient, an opposite spin torque effect inL1(0)FePt is demonstrated. At last, the role of the disorder gradient in generating a substantial torque in a single ferromagnet is supported by theoretical calculations. These results will push forward the frontier of material systems for generating spin torques and will have a transformative impact on magnetic storage and spin memory devices with simple architecture, ultrahigh density, and readily application.
