Xue Lin, He Chaoyu, Yang Zhi, Zhang Zhiyi, Xu Lichun, Fan Xiaopeng, Zhang Longlong, Yang Lingzhen
College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan, 030024, China.
Hongzhiwei Technology (Shanghai) Co. Ltd., 1599 Xinjinqiao Road, Pudong, Shanghai, China.
Phys Chem Chem Phys. 2022 Jul 21;24(28):17263-17270. doi: 10.1039/d2cp01213h.
It has been found that magnetism in two-dimensional (2D) transition metal dichalcogenides can be realized by properly introducing vacancies and applying strain. However, no work has clearly clarified the modulation of such 2D magnetism under a sweeping strain. Thus we were motivated in this work to investigate the mechanical and electronic properties of the monolayer MS (M = Mo, W) with symmetric S vacancy defects under sweeping strain. The results show that the local structure of the M atoms in MS around the defect undergoes a reversible phase transition from a triangular shape (Tri-3M) with short M-M bonds, to a circular one (Cir-6M-12S) with larger M-M bonds as the planar strain increases. The critical tensile strain for the transition from Tri-3M to Cir-6M-12S are 12.53% for MoS and 11.46% for WS, while the critical compressive strain for the reversal from Cir-6M-12S to Tri-3M are -3.60% and -2.16%, respectively. In particular, we find that the magnetism can be continuously modulated and undergoes a hysteresis loop behavior under the sweeping strains, with the residual magnetism being 2 . Our work theoretically predicts the promising prospect for exploring low-dimensional semiconductor spintronic devices working without applying a magnetic field.
研究发现，通过适当引入空位和施加应变，可以在二维（2D）过渡金属二硫属化物中实现磁性。然而，尚无研究明确阐明在扫描应变下这种二维磁性的调制情况。因此，我们开展这项工作，研究具有对称硫空位缺陷的单层MS（M = Mo，W）在扫描应变下的力学和电子性质。结果表明，随着平面应变增加，MS中缺陷周围M原子的局部结构经历了从具有短M-M键的三角形形状（Tri-3M）到具有较大M-M键的圆形形状（Cir-6M-12S）的可逆相变。从Tri-3M到Cir-6M-12S转变的临界拉伸应变，对于MoS为12.53%，对于WS为11.46%，而从Cir-6M-12S到Tri-3M逆转的临界压缩应变分别为-3.60%和-2.16%。特别地，我们发现磁性可以在扫描应变下连续调制并呈现磁滞回线行为，剩余磁性为2。我们的工作从理论上预测了探索无需施加磁场即可工作的低维半导体自旋电子器件的广阔前景。
