Novel electronic and magnetic features in XC (X = Si and Ge) monolayers induced by doping with group-VA atoms

Abstract

Great research efforts have been made to introduce high-temperature magnetism in two-dimensional (2D) materials for spintronic applications. In this work, the electronic and magnetic properties of bare and group-VA (N, P, and As) atom doped XC (X = Si and Ge) monolayers have been systematically studied to unravel the doping effects. The pristine monolayers are non-magnetic semiconductors, where the charger transfer from Si and Ge atoms to the C atom is responsible for their wide band gap. The C and X sublattices are identified as preferable doping sites for N and P/As atoms, respectively. Significant magnetism is induced by doping, where the magnetization is stronger in SiC (total magnetic moment of 1 μ_B) than in GeC (total magnetic moment between 0.69 and 0.98 μ_B). The magnetic properties of the N-doped SiC monolayer are produced mainly by the first Si neighbor around the doping site, meanwhile P and As atoms induce magnetism in the remaining cases. In addition, the doped systems show diverse electronic structures including metals, half-metals, and magnetic semiconductors, which are regulated mainly by the p_z state of the magnetized atoms. The results presented herein may introduce an efficient way to functionalize group-IVA based 2D semiconductor materials for potential spintronic applications by doping with non-magnetic group-VA atoms.