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 WSe ₂ monolayer system. The calculated results show that the W-rich condition is more energetically favorable for the Ir doped WSe ₂ system compared to the Se-rich one. Moreover, the Ir doped WSe ₂ systems under the different strains always possess PMA and the PMA can be enhanced by compressive strain. Importantly, the PMA of the Ir doped WSe ₂ 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 x 2 - y 2 and d xy orbitals of Ir atom. The study provides a potential route to effectively tune PMA of the Ir doped WSe ₂ system and promotes its future applications in ultrahigh density data storage devices.