High Curie temperature and perpendicular magnetic anisotropy in Mn-doped MoSe2 monolayer induced by O and S impurities

Abstract

Perpendicular magnetic anisotropy (PMA) and high Curie temperature are essential in two-dimensional (2D) materials for spintronic applications. In this work, we investigate the electronic and magnetic properties of MoSe₂ monolayer under effects of doping with Mn atoms. Pristine MoSe₂ monolayer is a $K-K$ direct-gap semiconductor with a band gap of 1.44 eV. Single Mn impurity leads to the emergence of the half-metallicity in MoSe₂ monolayer. 1Mn@MoSe₂ system has a total magnetic moment of 1.00 ${\mu }_B$. Its magnetic properties emerge mainly from Mn atom, with small contributions of their neighboring Se and Mo atoms that exhibit antiparallel alignment to Mn. The ferromagnetic semiconductor nature with a total magnetic moment of 2.00 ${\mu }_B$ and high Curie temperature of 599.59 K is found in 2Mn@MoSe₂ system. Moreover, the calculated magnetic anisotropy energies indicate the in-plane magnetic anisotropy (IMA) of Mn-doped MoSe₂ systems. Further, the IMA-to-PMA switching is achieved by incorporating O and S impurities. In these cases, the ferromagnetic semiconductor nature is preserved, however Curie temperature is reduced to 402.31 and 444.86 K, respectively. In addition, the surface formation energy analysis indicates that the doped and codoped MoSe₂ systems are formed at Mo-poor and Se-poor conditions. Our findings show a way to generate new 2D magnetic materials with perpendicular magnetic anisotropy and high Curie temperature, with great potential to be applied in the spintronics field as part of ultra thin perpendicular magnetic tunnel junctions.