Thermal stability and electronic and magnetic properties of atomically thin 2D transition metal oxides

Two-dimensional (2D) transition metal oxides (TMOs) are an emerging class of nanomaterials. Using density functional theory and
ab initio molecular dynamics (AIMD) simulations, we carried out a systematic study of atomically thin metal oxide phases with
compositions MO, M2O3, and MO2, for transition metal elements Sc, Ti, V, Cr, and Mn. We identified nine thermally stable structures
that may be realized as free-standing nanosheets: hexagonal h-Sc2O3, h-V2O3, and h-Mn2O3; hexagonal t-VO, t-CrO, and t-MnO; and
square sq-TiO, sq-VO, and sq-MnO. The t-MO phases are novel hexagonal structures which emerged naturally from phase
transformations observed during AIMD simulations. The 2D TMOs were found to exhibit a wide range of remarkable electronic and
magnetic properties, indicating that they are bright candidates for electronic and spintronic applications. Most exceptional in this
regard is h-V2O3, that is the only phase that has been experimentally realized so far, and was found to be a ferromagnetic half-metal
with Dirac-cone-like bands.