Electronic structures and magnetic properties of two-dimensional honeycomb-kagome structured V[formula omitted]O[formula omitted] monolayer and V[formula omitted]O[formula omitted]/M(0001) (M=Zr and Hf) system

Abstract

Transition metal oxides exhibit a variety of atomic structures with associated exotic electronic and magnetic properties, being expected to act an important role in two-dimensional spintronics applications. Based on density functional theory, the electronic structures and magnetic properties of V2O3 monolayer with a two-dimensional honeycomb-kagome configuration were systemically studied by first-principles calculations. The atomic thin V2O3 monolayer was found to be an intrinsic half-metallic ferromagnetism with a Curie temperature up to 450 K evaluated by Monte Carlo simulations, exhibiting an excellent mechanical flexibility and an exceptional dynamical stability. Dominated by exchange interactions between the nearest neighboring V ions in a high spin state of d2↑, some Dirac cones and flat bands emerge around the Fermi level, which were demonstrated by a tight-binding approach in further. The Dirac electrons exhibit a high Fermi velocity about 3.39×105 m/s and a rather large gap about 23.5meV opened with the account of spin–orbital coupling. A structure-polarization and a sizable band gap can be introduced into V2O3 monolayer by heavy bi-axial compressive strains. Then the electronic and magnetic properties of V2O3/M(0001) (M=Zr and Hf) interface system were investigated in a series of configurations. It was found that the V2O3 monolayer transforms into antiferromagnetic with a structure-polarization and a modified electronic structure caused by the strong interactions between the monolayer and substrates. Our investigations provide a theoretical guidance and a direct interest for the two-dimensional magnetic materials on metal substrates.