Evolution of structural () relaxation time anomalies in GexSe1-x chalcogenide glasses

Abstract

We examine enthalpy relaxation across the chalcogenide glass series GexSe 1-x ,preparedovercloseby compositions using conventional melt-quenching technique. We estimate the timescale Τ(Tg ) characterizing enthalpic relaxation near the kinetic glass transition temperature, using the nonreversing heat-flow data obtained from modulated differential scanning calorimetry measurements over a wide range of compositions (2.1 ≤ r ≤2.8, r =2x + 2). Anomalies in the enthalpy-relaxation characteristic-times Τg(r)areidentified with three rigidity-transitions encountered in successive Ge-doping of polymeric selenium chains.