The isotropic Compton profile difference across the phase transition of VO$_2$

TL;DR

This study investigates the changes in the isotropic Compton profile of VO$_2$ during its phase transition, demonstrating its potential for probing electronic structure in complex solids, with experimental results compared to DFT calculations.

Contribution

It provides the first detailed analysis of Compton profile differences across VO$_2$'s phase transition, linking experimental observations with theoretical calculations.

Findings

Observable Compton profile signal across phase transition

Agreement in shape between experiment and DFT calculations

Discrepancies in amplitude likely due to correlation effects

Abstract

We studied the isotropic Compton profile of the prototypical oxide VO$_2$ across the temperature induced electronic and structural phase transition at T$_C$ $\approx$ 340 K. We show that the phase transition leaves an observable signal, which facilitates Compton scattering studies of electronic structure and phase transitions in complex solids in powder form. We compare the experimental results with density functional theory calculations and find agreement in the shape of the difference profile, although the amplitude of the observed features is overestimated. The origin of the disagreement is discussed and we argue that it mainly originates mostly correlation effects beyond our current calculations and possibly to some extent, from thermal motion.