Structural and electronic properties of epitaxial V₂O₃thin films

Abstract

Thin films of V2O3 with thickness 4–300 nm were grown on -oriented sapphire substrates by reactive dc magnetron sputtering. X-ray diffraction, pole figure measurements and scanning tunnelling microscopy show high crystallinity and epitaxy to the substrate with a faceted surface structure, and the absence of strain. Measurements of the electrical resistivity, scanning tunnelling and x-ray absorption spectroscopy show a metal–insulator transition near 150 K that is connected with the opening of an energy gap and a characteristic modification of the absorption spectrum at the vanadium-2p and oxygen-1s edges. These observations reveal that the films have bulk-like properties.