YIG/Ta/CoTb/Pt多层膜中基于自旋轨道矩的全电学垂直磁矩翻转  

Field-free spin-orbit torque-induced perpendicular magnetization switching in YIG/Ta/CoTb/Pt

作　　者：孟德全 何文卿 张雨 刘耿硕 游龙 万蔡华[2] 梁世恒 MENG DeQuan;HE WenQing;ZHANG Yu;LIU GengShuo;YOU Long;WAN CaiHua;LIANG ShiHeng(Faculty of Physics and Electronic Science,Hubei University,Wuhan 430062,China;Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China;Hubei Key Laboratory of Ferroelectric Materials and Devices,Wuhan 430062,China)

机构地区：[1]湖北大学物理与电子科学学院,武汉430062 [2]中国科学院物理研究所,北京100190 [3]华中科技大学光学与电子信息学院,武汉430074 [4]铁电压电材料与器件湖北省重点实验室,武汉430062

出　　处：《中国科学：物理学、力学、天文学》2022年第9期130-135,共6页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家重点研发计划(编号:2017YFA0206200,2022YFE0103300);国家自然科学基金(编号:11904088);武汉科技局项目(编号:2019010701011394)资助。

摘　　要：自旋轨道矩为设计新型自旋电子存储和逻辑器件提供了物理基础,而实现零磁场自旋轨道矩操控磁矩翻转是此类自旋电子器件应用的物理基础.本工作在钇铁石榴石(Yttrium Iron Garnet,YIG)磁性绝缘薄膜层上生长了Ta/CoTb/Pt亚铁磁性多层膜,利用YIG磁性绝缘层对具有垂直磁各向异性的CoTb薄膜施加磁偶极相互作用场,再辅以Ta和Pt层中叠加的自旋轨道矩,实现零外场下对CoTb磁矩的操控和翻转.实验上通过反常霍尔效应及反常霍尔电阻测量脉冲电流诱导的磁化翻转行为,并在磁光克尔显微镜下观察到了脉冲电流驱动的磁畴壁运动特征,发现对于YIG/Ta/CoTb/Pt器件,由于受到底层YIG的影响,亚铁磁CoTb的磁畴以条纹状特征进行运动和完成磁化翻转,这与Si/Ta/CoTb/Pt薄膜磁化翻转特性存在显著区别.本文对于自旋电子低功耗器件尤其是全电学驱动的自旋轨道矩器件的研究,具有参考意义和潜在应用价值.Spin-orbit torques(SOTs) provide a physical basis for designing new spintronic memory and logic devices. The key to the application is the realization of field-free SOT-driven magnetization switching. In this study, Ta/CoTb/Pt ferromagnetic multilayers were grown on yttrium iron garnet(YIG) magnetic insulating film. We achieved currentinduced CoTb magnetization switching under zero magnetic field by using the magnetic dipole interaction field generated by the YIG magnetic insulating layer applied to the CoTb film with perpendicular magnetic anisotropy and the spin torque generated from Ta and Pt spin source layers. Experimentally, we measured the magnetization reversal behavior induced by pulse current through anomalous Hall effect and anomalous Hall resistance and observed the magnetic domain wall motion characteristics driven by pulse current under the magneto-optical Kerr microscope.Moreover, due to the influence of the magneto-optical Kerr microscope, it was found that for YIG/Ta/CoTb/Pt devices,the magnetic domain of ferromagnetic CoTb moves and completes magnetization switching by forming stripe-like features, which is significantly different from the magnetization switching characteristics of the Si/Ta/CoTb/Pt film. Our results may provide a new degree of freedom for the potential application value of the research of spintronic low-power devices, particularly field-free SOT-driven switching-based devices.

关 键 词：自旋电子学 自旋轨道矩 磁畴 

分 类 号：O469[理学—凝聚态物理]