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 Å 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.