Correlation between strain and the metal-insulator transition in epitaxial V2O3 thin films grown by Molecular Beam Epitaxy

We report on the deposition of high quality epitaxial V2O3 thin films on (0001) oriented Al2O3 substrates with Molecular Beam Epitaxy. Growth of smooth V2O3 films with root mean square roughness values down to 1 angstrom exhibiting both bulk-like and non bulk-like electrical properties has already been reported in a previous contribution. In this work, the lattice parameters and strain state of deposited films are extracted from both out-of-plane and grazing incidence in-plane X-ray diffraction measurements. Resistivity measurements are performed as a function of temperature using the four-point probe method. We observe a correlation between the in-plane tensile strain and the electrical properties, in particular the room-temperature resistivity. We also compare the electrical data of our V2O3 thin films with the features of the V2O3 bulk phase diagram. (C) 2011 Elsevier B.V. All rights reserved.