Thickness dependence of electronic phase transitions in epitaxial V2O3 films on (0001) LiTaO3

Single crystal epitaxial thin films of V2O3 were grown on (0001) LiTaO3 by pulsed laser deposition. X-ray diffraction and atomic force microscopy data show that the deposits were initially pseudomorphic, that they underwent plastic relaxation at a critical thickness of approximate to 16 nm, and that relaxation is accompanied by the development of surface roughness, increasing with deposit thickness. These effects lead to changes in electrical properties of the films as a function of temperature. As film thickness increases the properties go from insulator-insulator to metal-insulator, then metal-metal transitions. The thickest films (> 200 nm) remained metallic over the temperature range of the measurements. (C) 2008 American Institute of Physics.