Highly Oriented VO[sub 2] Thin Films Prepared by Sol-Gel Deposition

Abstract

Highly oriented thin films were grown on sapphire substrates by a sol-gel method which includes a low-pressure annealing in an oxygen atmosphere. This reduction process effectively promotes the formation of the phase over a relatively wide range of pressures below 100 mTorr and temperatures above 400°C. X-ray diffraction analysis showed that as-deposited films crystallize directly to the phase without passing through intermediate phases. films have been found to be with [100]- and [010]-preferred orientations on and substrates, respectively. Both films undergo a metal-insulator transition with an abrupt change in resistance, with different transition behaviors observed for the differently oriented films. For the [010]-oriented films a larger change in resistance of and a lower transition temperature are found compared to the values obtained for the [100]-oriented films.