CO2 Entropy Depletion-induced 2D Amorphous Structure in Non-van der Waals VO2

Abstract

Few studies focus on the plastic deformations of inorganic semiconductors because they are usually brittle and do not deform easily. Here, a peculiar internal shear stress originated from the entropy deletion of CO₂ in the tunnels of non-van der Waals VO₂ crystal, is employed to introduce hierarchical plastic deformations, including dislocations, point vacancies, twins, and amorphous bands. The strength of such stress field increases by more than three orders of magnitude compared to that of external experimental CO₂ pressure. We further demonstrate that 2D amorphous structures can be obtained by the synergetic effect of hierarchical deformations in 3D crystal.

Keywords: 2D amorphous materials; VO2; hierarchical plastic deformations; internal shear stress; supercritical CO2.