Journal of Materials Chemistry C

Versatile electronic properties of atomically layered ScO2† G. C. Loh*ab and Ravindra Pandey*a In recent years, graphene and transition metal dichalcogenides (TMDs) have been at the forefront of candidate materials for next-generation electronic devices. In this study, we will consider transition metal oxides (TMOs), which are a class of materials that can exist in two-dimensional geometries, but exhibit unique properties due to the strong correlation between electrons. Density functional theory calculations under the generalized-gradient approximation with on-site Coulomb interactions (GGA + U) are performed to investigate the (a) geometry, (b) energetics, (c) electronic properties, (d) magnetic properties, and (e) chemical bonding of a layered TMO–scandium dioxide (ScO2) in its octahedral (T) and hexagonal (H) phases. The T-phase is a non-magnetic wide-band gap semiconductor with a band gap of 3.75 and 3.73 eV for the monolayer and bilayer, respectively. The H-phase monolayer is an anti-ferromagnetic (AFM) metal while the bilayer is metallic and has a ferromagnetic (FM) and an AFM configuration, which degenerate in energy. The metallicity and magnetic coupling between atoms in the H-phase are predominantly governed by the O-pz states. The analysis of the chemical topology using