2022年 第12卷 第5期
《工程（英文）》 >> 2022年 第12卷 第5期 doi: 10.1016/j.eng.2021.09.018
基于高垂直磁各向异性L10 FePt单层膜的电流驱动SOT磁化翻转研究
a School of Automation, China University of Geosciences, Wuhan 430074, China
b Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems, China University of Geosciences, Wuhan 430074, China
c School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
d China Resources Microelectronics Limited, Shanghai 200072, China
e Shenzhen Huazhong University of Science and Technology Research Institute, Shenzhen 518000, China
f Wuhan National high magnetic field center, Huazhong University of Science and Technology, Wuhan 430074, China
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摘要
本研究利用自旋轨道力矩（SOT）在单层L10 FePt 铁磁层中实现了电流驱动的部分磁化翻转，其中L10FePt 具有高垂直各向异性，Ku⊥为1.19 × 107 erg‧cm−3 （1 erg‧cm−3 = 0.1 J‧m−3）。与传统Ta/CoFeB/MgO 结构相比，L10 FePt 的SOT效率（βDL）要高几倍，可达8 × 10−6 Oe∙(A‧cm−2)−1（ 1 Oe = 79.57747 A‧m−1）。L10 FePt的SOT效应起源于FePt 内部分布不均匀的位错和缺陷造成的结构反演对称性破缺。进一步，采用MgO和SrTiO3 （STO）两种衬底制备FePt 自旋器件，基于MgO衬底的FePt 具有颗粒状结构，而生长于STO衬底上的FePt 则为连续结构。研究发现，基于MgO衬底的FePt 器件具备更高的SOT等效场及SOT效率，且FePt 的SOT效率不仅取决于溅射温度导致的化学有序度变化，还与晶格失配导致的微观结构变化有关。本文的研究可为基于SOT效应的高热稳定性电致磁记录提供有效的方法。
参考文献
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