Intermediate Phase in Germanium-Selenide glasses: A Theoretical and Experimental Study

TL;DR

This paper combines theoretical ab initio molecular dynamics simulations and experimental XANES measurements to investigate the Intermediate Phase in GexSe1-x glasses, revealing atomic and electronic signatures of this phase.

Contribution

It provides a comprehensive atomic-level picture of the Intermediate Phase in Ge-Se glasses supported by both simulations and experimental data.

Findings

MD models reproduce the XANES edge shift across the IP

Electronic signatures of the IP are identified in XANES measurements

Atomic structure changes correlate with the IP in Ge-Se glasses

Abstract

A theoretical and experimental study of the Intermediate Phase (IP) in GexSe1-x is presented. Based on ab initio molecular dynamics (MD) models of these glasses, a generic atomic picture of the IP is discussed thoroughly. X-Ray Absorption Near Edge Structure (XANES) measurements on Ge-Se glasses over a wide range including the IP window are presented to show the electronic signature of the IP in the form of the shift in the absorption edge with the Ge content. It is shown that MD based models clearly reproduce that shift.