A NOVEL WET PROCESS FOR THE PREPARATION OF VANADIUM DIOXIDE THIN-FILM

Thin films of vanadium oxide have been prepared from an aqueous soluti on system of (V2O5-HF aq.) with the addition of aluminium metal by a n ovel wet-preparation process which is called liquid-phase deposition ( LPD). From X-ray diffraction measurements, the as-deposited film was f ound to be amorphous and it was then crystallized to V2O5 by calcinati on at 400 degrees C under an air flow. In contrast, the monoclinic VO2 phase was obtained when the deposited film was calcined under a nitro gen atmosphere. The deposited film showed excellent adherence to the s ubstrate and was characterized by a homogeneous flat surface. The depo sited VO2 film exhibited a reversible semiconductor-metal phase transi tion around 70 degrees C and its transition behaviour depended on the way in which the film was prepared.