Structural Phase Transition of Multilayer VSe₂

Abstract

Vanadium diselenide (VSe₂), a member of the transition metal dichalcogenides (TMDs) family, is emerging as a promising two-dimensional (2D) candidate for the electronic and spintronic device with exotic properties including charge/spin density wave and ferromagnetism. The bulk crystal VSe₂ exists in a crystallographic form of <i>1T</i>-phase with metallic behavior. In this paper, we report a structural phase transition of multilayer VSe₂ from <i>1T</i> to <i>2H</i> through annealing at 650 K, accompanying a metal-insulator transition. We observe that the <i>2H</i>-phase is more thermodynamically favorable than the <i>1T</i>-phase at 2D.