Enhanced perpendicular magnetic anisotropy in single Ir doped WSe2 monolayer by the application of small strain: first-principles study

The tunable large perpendicular magnetic anisotropy (PMA) in an atomically thin layer is greatly essential for ultrahigh density data storage devices. Here, using first-principles calculations, we studied the effect of strain on the stability and the PMA of the single Ir doped WSe2 monolayer system. The calculated results show that the W-rich condition is more energetically favorable for the Ir doped WSe2 system compared to the Se-rich one. Moreover, the Ir doped WSe2 systems under the different strains always possess PMA and the PMA can be enhanced by compressive strain. Importantly, the PMA of the Ir doped WSe2 system under the -2% compressive strain is nearly double that of strain-free system. We elucidate that the underlying mechanism of the compressive strain effect comes from the increase of the positive contribution from spin-orbit coupling effects between same spin d(x2-y2) and d(xy) orbitals of Ir atom. The study provides a potential route to effectively tune PMA of the Ir doped WSe2 system and promotes its future applications in ultrahigh density data storage devices.