Composition effect on the pre-crystallization and crystallization characteristics for Se90-xTe10Agx

Abstract

The pre-crystallization and crystallization characteristics for Se90-xTe10Agx (where x = 4, 6 and 8 at.%) glasses were studied in this work by means of DSC under the non-isothermal conditions. Double stage endothermic glass transition, double stage exothermic crystallization and a single stage endothermic melting peaks were observed in the DSC curves. The annealed samples were then examined using XRD technique and the dominant crystalline phase has been identified. The average crystal sizes for the dominant crystalline phase in the annealed samples were calculated using Debye–Scherrer's formula and the effects of increasing Ag content are detailed. The Hrubý parameter values were assigned to the glasses under study. Moreover, the activation energies of the glass transition were calculated using different approaches at the glass transition temperatures and at different conversions. Also, the fragility index was calculated as a function of conversion and the glasses are found to mutate from being more fragile to be more strong throughout the relaxation process. On the other hand, a simple Gaussian function was able to deconvolute the crystallization overlapping peaks and the crystallization kinetics were calculated.