Formation of Vanadium Oxide (V-O System) Graded Compounds under Strong Gravitational Field

Abstract

Strong gravitational field induces sedimentation of atoms due to the different body forces acting on respective atoms, and gives a tool for controlling elemental compositions in condensed matter. Vanadium oxide (V-O system) has large contrast in phases like VO, V2O3, VO2, V2O5 etc., and shows the respective interesting diverse electrical and optical properties. We performed a strong-gravity experiment (0.397106G at 400°C for 24 hours) on a V2O5 polycrystal using the high temperature ultracentrifuge to examine the composition change and further the structure change. It was found by the XRD and Raman scattering method that VO2 and V2O3 phases appeared and the amounts were increased, while one of the V2O5 phase decreased gradually along with the increasing gravitational field.