Miao Yaping, Huang Yuhong, Bao Hongwei, Xu Kewei, Ma Fei, Chu Paul K
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, People's Republic of China. Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, People's Republic of China.
J Phys Condens Matter. 2018 May 31;30(21):215801. doi: 10.1088/1361-648X/aabd46. Epub 2018 Apr 11.
First-principles calculations are conducted to study the electronic and magnetic states of Mn-doped monolayer MoS under lattice strain. Mn-doped MoS exhibits half-metallic and ferromagnetic (FM) characteristics in which the majority spin channel exhibits metallic features but there is a bandgap in the minority spin channel. The FM state and the total magnetic moment of 1 µ are always maintained for the larger supercells of monolayer MoS with only one doped Mn, no matter under tensile or compressive strain. Furthermore, the FM state will be enhanced by the tensile strain if two Mo atoms are substituted by Mn atoms in the monolayer MoS. The magnetic moment increases up to 0.50 µ per unit cell at a tensile strain of 7%. However, the Mn-doped MoS changes to metallic and antiferromagnetic under compressive strain. The spin polarization of Mn 3d orbitals disappears gradually with increasing compressive strain, and the superexchange interaction between Mn atoms increases gradually. The results suggest that the electronic and magnetic properties of Mn-doped monolayer MoS can be effectively modulated by strain engineering providing insight into application to electronic and spintronic devices.
通过第一性原理计算研究了晶格应变下Mn掺杂单层MoS的电子态和磁态。Mn掺杂的MoS表现出半金属和铁磁（FM）特性，其中多数自旋通道呈现金属特征，而少数自旋通道存在带隙。对于仅掺杂一个Mn的单层MoS的较大超胞，无论在拉伸应变还是压缩应变下，FM态和1 µ 的总磁矩始终保持。此外，在单层MoS中若两个Mo原子被Mn原子取代，拉伸应变会增强FM态。在7%的拉伸应变下，磁矩增加至每晶胞0.50 µ 。然而，Mn掺杂的MoS在压缩应变下变为金属和反铁磁态。随着压缩应变增加，Mn 3d轨道的自旋极化逐渐消失，Mn原子间的超交换相互作用逐渐增强。结果表明，通过应变工程可有效调控Mn掺杂单层MoS的电子和磁性能，为其在电子和自旋电子器件中的应用提供了思路。
