Alloying two-dimensional VSiN to realize an ideal half-metal towards spintronic applications.

Modulating the electronic properties of VSiN with high Curie temperature to realize an ideal half-metal is appealing towards spintronic applications. Here, by using first-principles calculations, we propose alloying the VSiN monolayer via substitutive doping of transition metal atoms (Sc-Ni, Y-Mo) at the V site. We find that the transition metal atom (except the Ni atom) doped VSiN systems have dynamical and thermal stability. The doping of transition metal atoms can modulate the electronic structure of VSiN. Especially, the doping of the Sc/Y atom transforms VSiN into an ideal half-metal, while the doping of the Ti/Zr atom leads to a half-semiconductor. For the half-metallic Sc- and Y-doped VSiN devices, the magnetoresistance ratios up to 10% and 10% are achieved, respectively. When the magnetization direction is parallel, the spin filtering efficiency of both devices reaches up to 100% at a low bias voltage, independent of the bias direction. When the magnetization direction is antiparallel, both show a dual spin filtering effect. Our findings offer a theoretical reference for modulating the electronic properties of two-dimensional materials towards spintronic applications.