Comparative study on the electronic and magnetic properties of two-dimensional Janus materials: h-SVSiN2 and t-SVSiN2

Search for two-dimensional magnetic semiconductors and half-metals are particularly significant for spintronic applications. By substituting N-Si-N atom group with S atoms on one side of SVSiN2 monolayer, two Janus monolayers: h-SVSiN2 and t-SVSiN2 were proposed. Through density functional theory, their electronic and magnetic properties have been studied systematically. Our results show that Janus h-SVSiN2 monolayer is an indirect semiconductor with intrinsic ferromagnetic order, while Janus t-SVSiN2 monolayer exhibits half- metallic feature. They both possess easy-plane magnetic anisotropy, with Curie temperature of 290 and 136 K for h-SVSiN2 and t-SVSiN2 monolayers, respectively. The electronic structures can be regulated by biaxial strain, such as semiconductor to half-metal transition. A spintronic device based on t-SVSiN2 monolayer has been designed, showing high magnetoresistance ratio and excellent spin filtering effect. These findings imply that Janus SVSiN2 monolayers are promising for 2D magnetism and spintronics.