Investigation of phase transition mechanism in vanadium oxide thin films

Thin film materials with "smart" properties which react with temperature variations, electrical or magnetic fields, and pressure variations, attracted great attention in recent years. Vanadium dioxide thin films belong to this family of "smart materials" by having a first order phase transition metal-semiconductor. These films display a variety of conductivities under heating in the vicinity of Curie temperature. The electrical properties of vanadium dioxide films were studied in past and found to be outstanding. This paper deals with the electrical properties of specific vanadium oxide thin films, deposited on various substrates. We have been able to show that the electrical transport mechanism of the obtained vanadium oxide films differs in low and high electrical fields. In low electrical fields, conductivity is obtained by Schottky transport mechanism, whereas in high electrical fields conductivity ranges from Ohmic mechanism for low fields to Poole-Frenkel for higher fields.