Ren Lizhu, Liu Liang, Shu Xinyu, Lin Weinan, Yang Ping, Chen Jingsheng, Teo Kie Leong
Department of Electrical and Computer Engineering, National University of Singapore, 117576, Singapore.
Department of Materials Science and Engineering, National University of Singapore, 117575, Singapore.
ACS Appl Mater Interfaces. 2021 Apr 21;13(15):18294-18300. doi: 10.1021/acsami.1c01720. Epub 2021 Apr 6.
Current-induced spin-orbit torque (SOT) switching of magnetization has attracted great interest due to its potential application in magnetic memory devices, which offer low-energy consumption and high-speed writing. However, most of the SOT studies on perpendicularly magnetized anisotropy (PMA) magnets have been limited to heterostructures with interfacial PMA and poor thermal stability. Here, we experimentally demonstrate a SOT magnetization switching for a ferrimagnetic D0-MnGe film with high bulk PMA and robust thermal stability factor under a critical current density of 6.6 × 10 A m through the spin Hall effect of an adjacent capping Pt and a buffer Cr layer. A large effective damping-like SOT efficiency of 2.37 mT/10 A m is determined using harmonic measurements in the structure. The effect of the double-spin source layers and the negative-exchange interaction of the ferrimagnet may explain the large SOT efficiency and the manifested magnetization switching of MnGe. Our findings demonstrate that D0-MnGe is a promising candidate for application in high-density SOT magnetic random-access memory devices.
电流诱导的自旋轨道矩（SOT）磁化翻转因其在磁存储器件中的潜在应用而备受关注，这类器件具有低能耗和高速写入的特点。然而，大多数关于垂直磁化各向异性（PMA）磁体的SOT研究都局限于具有界面PMA且热稳定性较差的异质结构。在此，我们通过相邻覆盖层Pt和缓冲层Cr的自旋霍尔效应，在6.6×10⁶ A/m的临界电流密度下，对具有高体PMA和稳健热稳定性因子的亚铁磁性D0-MnGe薄膜进行了SOT磁化翻转的实验演示。利用该结构中的谐波测量确定了2.37 mT/（10⁶ A/m）的大有效类阻尼SOT效率。双自旋源层的作用以及亚铁磁体的负交换相互作用可能解释了MnGe的大SOT效率和明显的磁化翻转。我们的研究结果表明，D0-MnGe是高密度SOT磁随机存取存储器器件应用的有前途的候选材料。
