Magnetic properties in a IIIA-nitride monolayer doped with Ag: A density functional theory investigation

We present a density functional theory study on the electronic structures and magnetism of IIIA-nitride (AlN, GaN and InN) monolayer doped with Ag atoms. The results show that the IIIA-nitride binary compounds doped with low concentrations of Ag atoms are spin-polarized with 2.0 mu(B). Among them, single layer AlN and GaN doped with Ag atoms both demonstrate two possible ground states: ferromagnetic and antiferromagnetic. In contrast, Ag-doped InN monolayer only exhibits ferromagnetic ground state with half-metallicity. Moreover, different doping concentration of Ag atoms results into various half-metal band-gaps. With increasing the concentration of Ag atoms, the energy gap of corresponding system significantly decreases. Under some suitable concentrations and sites of doped-Ag atoms, robust room-temperature ferromagnetism even can be realized in these systems. The above work shows a rich variety of electronic and magnetic properties in IIIA-nitride monolayer induced by Ag doping, which provides a simple and effective method to design new electronic and spintronic devices based on layered nanomaterials.