Optical properties of V2O3 in its whole phase diagram

TL;DR

This study provides a comprehensive optical analysis of V2O3 across its entire phase diagram, revealing how doping influences its electronic phases and low-energy electrodynamics, offering new insights into Mott-Hubbard physics.

Contribution

It presents the first detailed optical characterization of V2O3's phase diagram with doping, highlighting differences in electrodynamics and phase separation phenomena.

Findings

Doping alters the antiferromagnetic gap and metallic properties.

Cr doping induces mesoscopic electronic phase separation.

Pure V2O3 exhibits short-lived quasiparticles at high temperature.

Abstract

Vanadium sesquioxide V2O3 is considered a textbook example of Mott-Hubbard physics. In this paper we present an extended optical study of its whole temperature/doping phase diagram as obtained by doping the pure material with M=Cr or Ti atoms (V1-xMx)2O3. We reveal that its thermodynamically stable metallic and insulating phases, although macroscopically equivalent, show very different low-energy electrodynamics. The Cr and Ti doping drastically change both the antiferromagnetic gap and the paramagnetic metallic properties. A slight chromium content induces a mesoscopic electronic phase separation, while the pure compound is characterized by short-lived quasiparticles at high temperature. This study thus provides a new comprehensive scenario of the Mott-Hubbard physics in the prototype compound V2O3.