Study of Enhanced Ferromagnetic Behavior of Mn-Doped 2D Janus Cr₂S₂I₂ Monolayer

In this work, we report the first-principle based study of the electronic properties of Mn-doped Cr2S2I2 (CrMnS2I2) monolayer for possible applications in various spin devices. The electric field (0.5 eV/Å) and compressive strain (5%) are applied externally on the Mn-doped Cr2S2I2 monolayer to study the impact on its magnetic properties. The long-range ferromagnetism is established by the exchange coefficient (J1). The exchange coupling is enhanced from 0.131 to 7.81 meV with the applied external electric field. The ferromagnetic behavior is confirmed in the pristine CrMnS2I2 monolayer and by two external methods. The FM monolayer shows perpendicular magnetic anisotropy (PMA) of 115.6 meV and high Curie Temperature of 476K (Tc). Both PMA and $\rm T_{\mathrm { c}}$ are increased to 792 meV and 497K with applied electric field and compressive strain. Since the studies material shows excellent potential for use in spintronic application we have estimated the spin barrier height (3.97) and filtration efficiency (64%) for CrMnS2I2 monolayer as spin filter as well as the tunnelling magnetoresistance (TMR) effect as FM layer in magnetic tunnel junctions (MTJ) respectively. The TMR is observed to increase from 78% to 359.52% by varying thickness of non-magnetic $\rm MoSe_{\mathrm {2}}$ spacer.