Prediction of two-dimensional M2As (M = Mn, Fe) with high Curie temperature and large perpendicular magnetic anisotropy

Abstract

Recently, with the miniaturization of electronic devices, there is an urgent need to use two-dimensional (2D) ferromagnetic materials with outstanding properties (such as high conductivity, better stability, etc.) and high Curie temperature (TC) in spintronic devices. By first-principles calculations based on density functional theory, we predict two new ferromagnetic metal monolayers M2As (M = Mn, Fe) with hight dynamic and thermal stabilities. Caculation results show that M2As monolayers possess high spin polarization ratio (27.3% for Mn2As and 52.6% for Fe2As), obvious out-of-plane magnetic anisotropy and large magnetic perpendicular anisotropy (101 μeV/Mn for Mn2As and 84 μeV/Fe for Fe2As). In addition, we found that the Mn2As monolayer exhibit high temperature ferromagnetism (TC = 450 K); while for the Fe2As monolayer, a high Curie temperature of 251 K was predicted. Moreover, we applied biaxial strain to the material to examine the changes in its magnetic properties and found that under a certain biaxial strain, Mn2As monolayer will have a ferromagnetic-antiferromagnetic phase transition, while Fe2As monolayer may exhibit a higher TC. Our findings render M2As (M = Mn, Fe) monolayers potential candidates for future spintronics and pave the way for exploring novel 2D magnetism in arsenic-based magnetic materials.