Zhou Yuqing, Xu Teng, Liang Xue, Zhao Le, Zhou Heng-An, Wang Zidong, Jiang Wanjun, Zhou Yan
School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China.
State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics, Beijing 100084, China.
Nanoscale. 2022 Sep 29;14(37):13526-13531. doi: 10.1039/d2nr02594a.
Magnetic domain walls (DWs) in rare-earth-transition-metal (RE-TM) ferrimagnetic alloys can be used as information carriers in nonvolatile spintronic devices. Due to the rich combinations of RE-TM elements (such as CoGd, FeGd, CoTb, and FeTb in our case), it is intriguing to reveal the characteristics of DW dynamics in these wide choices of RE-TM compounds. Through a systematic study of the DW motion in thin films with different compositions of stacking order Pt(3 nm)/(Fe,Co)(Gd,Tb)(∼8 nm)/Ta(3 nm), we show that the partially compensated ferrimagnets CoGd and FeGd can exhibit a faster DW motion under various (in-plane and out-of-plane) magnetic fields driven by current-induced spin-orbit torques. In stark contrast with the fast motion of domain walls in Gd-based ferrimagnets, we find that the CoTb system exhibits much slower DW dynamics, and the FeTb system shows no motion, but evolved into a multi-domain state upon applying current pulses. Our results demonstrate that ferrimagnets CoGd and FeGd are more suitable candidates for achieving ultrafast DW motion, which could be useful for developing spintronic memory and logic devices.
稀土过渡金属（RE-TM）亚铁磁合金中的磁畴壁（DWs）可作为非易失性自旋电子器件中的信息载体。由于RE-TM元素的丰富组合（如我们研究中的CoGd、FeGd、CoTb和FeTb），揭示这些广泛的RE-TM化合物中DW动力学特性很有趣。通过对具有不同堆叠顺序Pt(3 nm)/(Fe,Co)(Gd,Tb)(约8 nm)/Ta(3 nm)的薄膜中DW运动的系统研究，我们表明，在电流诱导自旋轨道扭矩驱动的各种（面内和面外）磁场下，部分补偿亚铁磁体CoGd和FeGd可表现出更快的DW运动。与基于Gd的亚铁磁体中畴壁的快速运动形成鲜明对比的是，我们发现CoTb系统表现出慢得多的DW动力学，而FeTb系统没有运动，但在施加电流脉冲后演变成多畴状态。我们的结果表明，亚铁磁体CoGd和FeGd是实现超快DW运动更合适的候选材料，这可能有助于开发自旋电子存储器和逻辑器件。
