Valence States of Layered Vanadium Chalcogenophosphates, VPS3and V0.78PS3

Abstract VPS3 and V0.78PS3 have been synthesized by calcination of elementary mixtures prepared in the ratios of V:P:S = 1:1:3 and 0.78:1:3, respectively. Their X-ray diffraction patterns indicate that they have the same crystalline structure and orientation of crystal growth. The X-ray photoelectron spectra of V2p show that the vanadium in V0.78PS3 is in a mixed valence state and the compound is expressed by the formula of (V0.32+V0.73+)0.78PS3.