Enhancement of spin-orbit torques in Ta/Co20Fe60B20/MgO structures induced by annealing
Enhancement of spin-orbit torques in Ta/Co20Fe60B20/MgO structures induced by annealing
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退火引起 Ta/Co20Fe60B20/MgO 结构自旋轨道扭矩的增强
DOI：
10.1063/1.4993765
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发表时间：
2017
期刊：
影响因子：
1.6
通讯作者：
Cao Jiangwei
中科院分区：
文献类型：
--
作者：
Zheng Yuqiang;Wang Tao;Su Xianpeng;Chen Yifei;Wang Ying;Lv Hua;Cardoso Susana;Yang Dezheng;Cao Jiangwei
用谐波电压法研究了Ta/CoFeB/MgO结构中的自旋轨道矩。结果表明，退火处理可以提高不同Ta厚度的薄膜叠层的类斯龙切夫斯基（HSL）和类场（HFL）有效场。对Ta层的晶相和霍尔栅器件电阻的研究表明，退火可以引起Ta层从α相到β相的相变，从而提高退火样品的HSL。电流诱导磁化开关实验表明，退火样品中的开关电流相应减少，因为它们的增强SOTs。
Spin-orbit torques (SOTs) in Ta/CoFeB/MgO structures are studied by harmonic voltage method. The results indicate that both Slonczewski-like (HSL) and field-like (HFL) effective field are enhanced by annealing in the film stacks with various Ta thicknesses. Investigation of the crystallographic phase of the Ta layers and resistance of Hall bar devices suggest that annealing may induce a phase transformation in the Ta layers from the α to the β phase, which results in the enhanced HSL of the annealed samples. Current-induced magnetization switching experiments revealed a corresponding decrease of the switching current in the annealed samples because of their enhanced SOTs.