Insulator-Metal Transition in TiGePt: a combined photoelectron spectroscopy, x-ray absorption spectroscopy, and band structure study

TL;DR

This study combines experimental and theoretical methods to investigate the electronic structure of TiGePt, revealing an insulator-metal transition associated with a structural phase change and significant electronic property alterations.

Contribution

It provides a comprehensive analysis of the electronic changes during the phase transition in TiGePt using spectroscopy and band structure calculations, highlighting the insulator-metal transition.

Findings

Insulator-to-metal transition observed in TiGePt

Significant band broadening and gap closing during transition

Structural phase change linked to electronic property change

Abstract

We present a combined experimental and theoretical study of the electronic structure of the intermetallic compound TiGePt by means of photoelectron spectroscopy, x-ray absorption spectroscopy and fullpotential band structure calculations. It was recently shown that TiGePt undergoes a structural phase transition by heating which is accompanied by a large volume contraction and a drastic change of physical properties, in particular a large decrease of the electrical resistivity. The present study revealed substantial differences in the electronic structure for the two TiGePt modifications, although they have the same nominal composition and show similar electron counts for particular valence band states. Our photoemission experiments and band structure calculations establish that an insulator-to-metal transition occurs with an appreciable band broadening and closing of the band gap