Raman spectroscopy and phonon dynamics in strained V2O3

Abstract

Transition metal oxides are known to have a strong interplay of many degrees of freedom giving rise to their rich phase diagrams with competing ground states. The Mott material V2O3 hosting a room- and low-temperature metal-insulator transition is a great example where electronic, structural and magnetic ordering are the directors at play. By combining first-principle calculations and Raman spectroscopy, we study the phonon dynamics of V2O3 to gain further understanding in the interplay of these ordering mechanisms driving the transitions. Firstprinciple calculations show that the Raman active vibrations correspond to the structural distortions occurring in the phase diagram. Additionally, Raman spectroscopy is performed on a unique series of epitaxial strained 1.5% Cr-doped V2O3 thin films, where both paramagnetic insulating, metallic, as well as intermediate electronic states are stabilized. This has led to identifying the importance of the local V-V dimer elongation that drives both the room- and low-temperature MIT in V2O3 compounds.