近年来，非磁重金属(HM)自旋霍尔效应的发现为利用自旋轨道相互作用来调控铁磁层磁化状态提供了可能。在非磁重金属/铁磁/氧化物这样的垂直磁化膜中，流经HM层中的电流作用于与之相邻近的铁磁层磁矩产生自旋轨道矩(SOT)，当电流的密度达到一个临界值时，SOT将会导致该铁磁层的磁矩发生翻转，但是目前SOT产生的基本物理机制还并不清楚，存在是界面Rashba效应还是自旋霍尔效应的争论。本申请从磁控溅射制备的CoFeB基新型垂直磁化膜的界面调控出发，分析HM/CoFeB/MgO 垂直磁化膜的磁各向异性及自旋相关的输运特性随界面掺杂元素或原位界面修饰的变化关系。着重于反常Hall效应和平面Hall效应的高次谐波测量手段，对电流诱导SOT驱动磁化翻转与HM/CoFeB/MgO 界面特性的关系进行系统的研究，揭示电流诱导SOT的物理机制，为电流诱导SOT在未来的自旋电子器件中的应用奠定基础。

Spintronics has had significant impact on information technology. A crucial component of this next generation of spintronic applications is the control of magnetic orientation with an electrical current. The approach is furthest developed in magnetic tunnel junctions, which utilize spin transfer torque to reversibly switch the magnetization in one of the layers. An alternative approach has been demonstrated in recent experiments on bilayer systems consisting of ultrathin ferromagnetic metal (FM) layers adjacent to heavy metals (HMs). In these systems, spin-orbit coupling is responsible for current-induced torques, which are termed spin orbit torques (SOT) and are to be distinguished from conventional spin transfer torque since the system requires strong spin orbit coupling to generate the spins. The spin Hall effect and the current-induced spin polarization (i.e., the Rashba effect) are considered to be the major sources that enable spin current generation and spin accumulation, respectively, in ultrathin magnetic heterostructures. To date, it is thus essential to understand the origin of spin orbit torques in order to apply them for possible applications in spintronic devices. In this proposal, we study the spin orbit torque in CoFeB/MgO heterostructures with HM-based underlayers as a function of the structure of interfaces to provide insight into spin transport and action of nonequilibrium spins on magnetization. We will study the perpendicular magnetic anisotropy, which strongly depends on the structure of interfaces in HM/CoFeB/MgO. The SOT possesses a damping like torque and a field like torque, and the size and direction of both components of the torque vary depending on the materials and the layers' structure and can be investigated by means of the harmonic anomalous Hall effect and planar Hall effect. And then the action of spins on the magnetic moments will be evaluated by measuring the effective magnetic field, which reflects the size and direction of the spin orbit torque. We hope that the study of HM/CoFeB/MgO thin films tunned by the control of interfaces can offer a possible route for the applications of spintronics.