Structural and electronic properties of epitaxial V2O3 thin films

Thin films of V2O3 with thickness 4-300 nm were grown on (11 (2) over bar0)-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-1 s edges. These observations reveal that the V2O3(11 (2) over bar0) films have bulk-like properties.