Preparation of YVO4 thin films by metal organic chemical vapor deposition

YVO4 films were reproducibly prepared on (0001) and (<11(2)over bar 0>) sapphire (alpha-Al2O3) substrates using metal organic chemical vapor deposition. X-Ray diffraction, transmission electron microscopy and X-ray energy dispersive spectroscopy were used to characterize the deposited films. It was found that under most growth conditions the films deposited on (0001) sapphire consisted of two layers, i.e. a stoichiometric bottom layer of YVO4 which was epitaxially grown on the substrate and a polycrystalline top layer of Y8V2O17. The effect of growth parameters, in particular the growth temperature, on the stability of the dual layer structured films was studied and a working model explaining the origin of dual layer structure was suggested. Based on these observations the method for the preparation of stoichiometric epitaxial one layer-structured YVO4 films with either an in-plane variant or a single crystal structure on (0001) and (<11(2)over bar 0>) sapphire (alpha-Al2O3) substrates, respectively, was presented. (C) 1998 Elsevier Science S.A. All rights reserved.