Increased metal-insulator transition temperatures in epitaxial thin films of V₂ O₃ prepared in reduced oxygen environments

Thin films of V2 O3 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 V2 O3 '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 V 2 O3. © 2011 American Institute of Physics.