Effect of ethanol vapour sorption on the semiconductor-metal phase transition in powdered vanadium dioxide

Abstract

We studied the effect of ethanol vapour on the parameters of the semiconductor-metal transition in a polycrystalline vanadium dioxide powder of the stable monoclinic phase a-VO2. It was synthesised by reducing vanadium pentoxide with oxalic acid while heated in air. The DC electrical resistance of the samples was studied between room temperature and 100оС in a tubular heater, in a microcompressor-generated air stream with saturated ethyl alcohol vapour. It was found that in the presence of ethanol vapour, the hysteresis loop shifted to higher temperatures by ten degrees and its cooling branch (corresponding to the transition of vanadium dioxide from the metallic phase to the semiconductor phase) became stepped.

Keywords

• vanadium dioxide
• semiconductor - metal phase transition
• ethanol vapour
• sorption