Sequential Electronic and Structural Transitions in VO2 Observed Using X-ray Absorption Spectromicroscopy

TL;DR

This study uses high-resolution x-ray absorption spectromicroscopy to reveal that in VO2, electronic transitions occur before structural changes during phase transitions, with intermediate states identified.

Contribution

It demonstrates the sequential nature of electronic and structural transitions in VO2 and identifies intermediate states, providing new insights into phase transition mechanisms.

Findings

Electronic transition precedes structural Peierls transition.

Intermediate spectrally isolated states are observed.

Transitions occur during both heating and cooling cycles.

Abstract

The popular dual electronic (Mott) and structural (Peierls) transitions in VO2 are explored using x-ray absorption spectromicroscopy with high spatial and spectral resolutions. It is found that during both heating and cooling, the electronic transition always precedes the structural Peierls transition. Between the two transitions, there are intermediate states that are spectrally isolated here.