Ferromagnetism and half-metallicity in two-dimensional MO (M=Ga,In) monolayers induced by hole doping

Identification of two-dimensional (2D) materials with magnetic properties has received strong research attention in the development of advanced spin-based devices. By means of first-principles calculations, we investigate the stability, electronic properties, and the hole-doping-induced magnetic properties of metal oxide ($M\mathrm{O}, M=\mathrm{Ga},\mathrm{In}$) monolayers. They are intrinsically nonmagnetic stable semiconductors, with high energetic, vibrational, and thermal stability. Hole doping can switch them from nonmagnetic to ferromagnetic and turn them into half-metals over a wide range of hole densities. Monte Carlo simulations predict that the highest Curie temperature of the GaO monolayer can reach \ensuremath{\sim}125 K. Our results indicate that monolayer $M\mathrm{O}$ could be eligible candidate materials for 2D spintronic devices.