Luo Feilong, Wong Qi Ying, Li Sihua, Tan Funan, Lim Gerard Joseph, Wang Xuan, Lew Wen Siang
School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
Department of Physics, School of Science, Lanzhou University of Technology, Lanzhou, 730050, PR China.
Sci Rep. 2019 Jul 25;9(1):10776. doi: 10.1038/s41598-019-47125-4.
The spin-orbit torque (SOT) effective fields, namely field-like and damping-like terms, depend on the thicknesses of heavy metal (HM) and ferromagnetic metal (FM) layers, in a stack comprising of HM/FM/HM or oxide. In this work, we report on the dependence of the SOT effective fields on the magnetization uniformity in the wires comprising of Ta/Co/Pt layer structure. SOT dependence on magnetization uniformity dependence was investigated by concurrent variation of the magnetization uniformity in Co layer and characterization of the SOT effective fields in each wire which excludes the layer thickness dependence influences. Our experimental results reveal that the field-like term decreases while the damping-like term increases with increasing Co magnetization uniformity. The magnetization uniformity influence on the effective fields is attributed to the spin Hall effect, which contributes to the SOT.
自旋轨道矩（SOT）有效场，即类场项和类阻尼项，取决于重金属（HM）和铁磁金属（FM）层的厚度，该结构由HM/FM/HM或氧化物组成。在这项工作中，我们报告了SOT有效场对由Ta/Co/Pt层结构组成的导线中磁化均匀性的依赖性。通过同时改变Co层中的磁化均匀性并对每根导线中的SOT有效场进行表征（排除层厚度依赖性影响），研究了SOT对磁化均匀性依赖性。我们的实验结果表明，随着Co磁化均匀性的增加，类场项减小而类阻尼项增加。有效场的磁化均匀性影响归因于自旋霍尔效应，它对SOT有贡献。
