School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
Sci Rep. 2017 Apr 20;7(1):972. doi: 10.1038/s41598-017-01079-7.
Spin-orbit torque (SOT) induced by electric current has attracted extensive attention as an efficient method of controlling the magnetization in nanomagnetic structures. SOT-induced magnetization reversal is usually achieved with the aid of an in-plane bias magnetic field. In this paper, we show that by selecting a film stack with weak out-of-plane magnetic anisotropy, field-free SOT-induced switching can be achieved in micron sized multilayers. Using direct current, deterministic bipolar magnetization reversal is obtained in Pt/[Co/Ni]/Co/Ta structures. Kerr imaging reveals that the SOT-induced magnetization switching process is completed via the nucleation of reverse domain and propagation of domain wall in the system.
自旋轨道扭矩（SOT）通过电流产生，作为控制纳米磁性结构中磁化的有效方法，引起了广泛关注。SOT 诱导的磁化反转通常借助于平面内偏置磁场来实现。在本文中，我们表明，通过选择具有弱面外各向异性的薄膜叠层，可以在微米级的多层膜中实现无场 SOT 诱导的切换。在 Pt/[Co/Ni]/Co/Ta 结构中使用直流，实现了确定性双极磁化反转。克尔成像显示，SOT 诱导的磁化反转过程是通过反向畴的成核和系统中畴壁的传播来完成的。
