Alloying two-dimensional VSi 2 N 4 to realize an ideal half-metal towards spintronic applications

Modulating the electronic properties of VSi N 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 VSi N 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 VSi N systems have dynamical and thermal stability. The doping of transition metal atoms can modulate the electronic structure of VSi N . Especially, the doping of the Sc/Y atom transforms VSi N 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 VSi N 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.