The activation energies at glass transition temperatures and dynamic fragility of (Se90Te10)100-x Inx glassy alloys

Abstract

Chalcogenide glasses of (Se90Te10)100-x Inx (x = 0, 3, 6, 9, 11) alloys are prepared by melt quench technique. Differential scanning calorimetry (DSC) technique with different heating rate is used to study the dependence of the glass transition temperature (Tg) and fragility dynamics m on the In content in the Se-Te matrix. It is observed an increase of Tg with increasing In content. The glass transition temperature is differently defined according to the different degree of conversion of the glass. The activation energy of the glass transition (Eg) is evaluated using Kissinger, Moynihan kinetic and the partial area (isoconversional) methods. Analysis of experimental data shows that Eg changes with the degree of conversion from the glassy to the supercooled phase. The variation of the fragility with indium content is attributed to the formation of network structure. The employed theoretical models to describe the kinetics of the glass transition are valid.