Increased metal-insulator transition temperatures in epitaxial thin films of V2O3 prepared in reduced oxygen environments

Thin films of V2O3 were grown epitaxially on c-plane sapphire substrates by oxygen plasma-assisted thermal evaporation. Reducing the amount of oxygen supplied during growth led to a nearly 50 K increase in V2O3's metal-insulator transition temperature to a temperature as high as 184 K. By systematically varying the oxygen pressure the transition temperature monotonically increased, which was accompanied by a concomitant increase in the room-temperature resistivity. These trends are consistent with a continuous change in the stoichiometry of V2O3. (C) 2011 American Institute of Physics. [doi:10.1063/1.3574910]