Wan Wenhui, Zhao Rui, Ge Yanfeng, Liu Yong
State Key Laboratory of Metastable Materials Science and Technology Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, People's Republic of China.
J Phys Condens Matter. 2022 Dec 14;35(6). doi: 10.1088/1361-648X/aca30c.
The search and design of two-dimensional (2D) magnetic semiconductors for spintronics applications are particularly significant. In this work, we investigated the electronic and magnetic properties of Janus structure based on Dirac half-metallic vanadium phosphide (VP) monolayer (ML) by first-principles calculations. Due to the vertical symmetry breaking, Janus VAsP ML becomes an intrinsic ferromagnetic semiconductor with a narrow band gap of 0.21 eV. We analyzed the electronic structure and origin of the in-plane easy axis in Janus VAsP. The electron effective mass is anisotropic and only 0.129 malong the-direction. The Curie temperatureTcand magnetic anisotropy energy (MAE) of Janus VAsP reach 490 K and 178 eV per V atom, respectively. A uniaxial tensile stainof 5% can increase its band gap and MAE to 0.39 eV and 210.6 eV per V atom while maintaining itsTcbeing above room temperature. Moreover, the direction of the easy axis can be changed between the in-plane- and-direction by a small uniaxial tensile strainof 2%. Our study can motivate further research on the design the magnetic semiconductors in Janus structures based on 2D Dirac half-metals for spintronics applications.
用于自旋电子学应用的二维（2D）磁性半导体的搜索和设计尤为重要。在这项工作中，我们通过第一性原理计算研究了基于狄拉克半金属磷化钒（VP）单层（ML）的Janus结构的电子和磁性特性。由于垂直对称性破缺，Janus VAsP ML成为具有0.21 eV窄带隙的本征铁磁半导体。我们分析了Janus VAsP中面内易轴的电子结构和起源。电子有效质量是各向异性的，沿方向仅为0.129 m。Janus VAsP的居里温度Tc和磁各向异性能量（MAE）分别达到490 K和每个V原子178 eV。5%的单轴拉伸应变可以将其带隙和MAE分别增加到0.39 eV和每个V原子210.6 eV，同时保持其Tc高于室温。此外，通过2%的小单轴拉伸应变，可以在面内方向和面外方向之间改变易轴方向。我们的研究可以推动基于二维狄拉克半金属的Janus结构中用于自旋电子学应用的磁性半导体设计的进一步研究。
