Enthalpy recovery during structural relaxation of Se 96In 4 chalcogenide glass

Abstract

Structural relaxation of isothermally and isochronally heat-treated Se 96In 4 chalcogenide glass in the glass transition region has been studied using a differential scanning calorimeter (DSC). The recovery of excess enthalpy Δ H excess has been calculated from the knowledge of excess apparent specific heat Δ C p,a ( T) and plotted as a function of annealing time t a. Δ H excess has been found to vary with t a; this variation follows a power-law behaviour and an expression of the form Δ H excess=Δ H o[ t a] y has been proposed to describe such variation . Following the Kissinger formalism the activation energy of structural relaxation E t, both for annealed and un-annealed samples, has been obtained. The so obtained values of structural relaxation activation energies are indicative of the fact that some kind of bond interchange has taken place which in turn accounts for the relaxation process in Se 96In 4 glass. From the knowledge of Δ H excess( T a, t a) and the corresponding activation energy, the activation energy spectra have also been drawn and discussed.