Selective Gamma-Ray Ionisation of Vanadium Oxides: Towards the Formation of VO2

Abstract

In this study, we report on the valence control of vanadium oxidation states towards stabilising VO2 thin films. X-ray diffraction measurements indicate that up to 300 kGy of gamma-ray radiation the VO2 phase remains monoclinic, with the crystallite size only varying slightly with the dose. X-ray photoemission spectroscopy indicates the presence of three oxide phases (VO2, V2O3 and V2O5) on the samples. A decrease in the oxidation states of V3+ and V5+ and an increase in the valence state V4+ are observed for irradiations up to 300 kGy, which favours the vanadium dioxide VO2 formation.