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

Abstract

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 ≈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.