Metal-insulator transition in nanocomposite VO_x films formed by anodic electrodeposition

摘要

The ability to grow VO_2 films by electrochemical methods would open a low-cost, easily scalable production route to a number of electronic devices. We have synthesized VO_x films by anodic electrodeposition of V_2O_5, followed by partial reduction by annealing in Ar. The resulting films are heterogeneous, consisting of various metallic/oxide phases and including regions with VO_2 stoichiometry. A gradual metal insulator transition with a nearly two order of magnitude change in film resistance is observed between room temperature and 140 ℃. In addition, the films exhibit a temperature coefficient of resistance of ～ -2.4%/℃ from 20 to 140℃.