Bulk defects induced coercivity modulation of Co thin film based on a Ta/Bi double buffer layer
Bulk defects induced coercivity modulation of Co thin film based on a Ta/Bi double buffer layer
复制标题
基于Ta/Bi双缓冲层的Co薄膜体缺陷诱导矫顽力调制
DOI：
10.1016/j.jmmm.2020.166388
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发表时间：
2020
影响因子：
2.7
通讯作者：
Yu Guanghua
中科院分区：
文献类型：
--
作者：
Xu Xiulan;Feng Guonan;Peng Wenlin;Han Gang;Yang Chen;Jia Yunlong;Guo Risi;Xiong Xiaodong;He Xin;Luo Junfeng;Hu Qiang;Hu Lang;Feng Chun;Yu Guanghua
This paper reports the effect of Ta/Bi double buffer layer on the magnetic properties of Co thin film. By inserting a Bi layer into the Ta/Co interface of Ta/Co/Ru, the coercive field is increased by about 6 times. Moreover, a further increase of coercivity is observed for the Ta/Bi/Co/Ru film after 450 degrees C annealing. X-ray photoelectron spectroscopy (XPS) reveals that the Bi atoms diffuse to film surface through the cobalt layer. Positron annihilation spectroscopy (PAS) indicates that the diffusion of Bi atoms promotes the formation of vacancies, which may increase the density of bulk defects in the film and enhance the pinning strength of the magnetic domains of Co. Besides, high-resolution transmission electron microscopy (HRTEM) results confirm the better crystallization of Co layer with a uniform orientation due to the Bi diffusion, which increases the energy barrier for nucleation and movement of the reversal domain. These two reasons lead to the increase of coercivity simultaneously. This finding provides a feasible avenue for the tunable coercive field by the defect engineering.
