Evolution of structural ({\alpha}) relaxation-time anomalies in GexSe1-x Chalcogenide glasses

TL;DR

This study investigates how enthalpy relaxation times in GexSe1-x chalcogenide glasses vary with composition, revealing anomalies that correspond to rigidity transitions during Ge-doping, using advanced calorimetry techniques.

Contribution

It provides new insights into the compositional dependence of enthalpy relaxation times and identifies anomalies linked to rigidity transitions in GexSe1-x glasses.

Findings

Enthalpy relaxation times vary with composition.

Anomalies mark rigidity transitions in the glass series.

Relaxation times are characterized near the glass transition temperature.

Abstract

We examine enthalpy relaxation across the chalcogenide glass series GexSe1-x, prepared over close-by compositions using conventional melt-quenching technique. We estimate the timescale {\tau}(Tg) characterizing enthalpic relaxation near the kinetic glass transition temperature, using the non-reversing heat-flow data obtained from MDSC (modulated differential scanning calorimetry) measurements over a wide range of compositions (2.1 {\lessthanequalto} r {\lessthanequalto} 2.8, r = 2x+2). Anomalies in the enthalpy-relaxation characteristic-times {\tau}g(r) are identified as marking rigidity-transitions encountered in successive Ge-doping of polymeric selenium chains.