Manipulation of perpendicular exchange bias and spin-orbit torques via MgO in Pt/Co/MgO films
Manipulation of perpendicular exchange bias and spin-orbit torques via MgO in Pt/Co/MgO films
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DOI：
10.1016/j.jmmm.2020.166822
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发表时间：
2020-08
影响因子：
2.7
通讯作者：
Zhiren Chen;Chunjiao Pan;Ning Wang;Qiu Mingxia-;Tao Lin;Jing Liu;Shunpu Li;Han Peigang-;Ji Shi
中科院分区：
文献类型：
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作者：
Zhiren Chen;Chunjiao Pan;Ning Wang;Qiu Mingxia-;Tao Lin;Jing Liu;Shunpu Li;Han Peigang-;Ji Shi
通过改变氧化镁层的厚度，研究了铂钴镁异质结中垂直交换偏置(PEB)和自旋轨道扭矩(SOT)的产生。结果表明，随着氧化镁厚度的增加，钴底层的氧化程度增加。在铂/钴/氧化镁薄膜中得到了较强的PEB，其阻挡温度比在铂/钴/氧化钴薄膜中高得多。此外，还发现氧化镁厚度对SOT的产生有显著的影响。当氧化镁厚度从0.8 nm增加到1.6 nm时，SOT值达到最大值。我们的结果揭示了氧化层在重金属/铁磁/氧化镁异质结构中的重要作用，并提供了一种通过氧化层来控制磁性能和SOT的方法。
We study the perpendicular exchange bias (PEB) and spin-orbit torque (SOT) generation in the Pt/Co/MgO heterostructure by changing the thickness of the MgO layer. We show that the oxidation of the beneath Co layer increases with the MgO thickness. Strong PEB is obtained in the Pt/Co/MgO films, which exhibits a much higher blocking temperature compared with that in the Pt/Co/CoO films. Furthermore, it is found that the MgO thickness has significant effect on the SOT generation. Maximum values of the SOTs are obtained with a 0.8 nm-thick MgO layer, which decreases by increasing the MgO thickness from 0.8 to 1.6 nm. Our results shed a light on the essential role of the MgO layer in the heavy metal/ferromagnet/MgO heterostructure, a typical material system in spintronic devices, and provide a way to manipulate the magnetic properties and the SOTs by oxide layers.