Crystallization and Glass Transition Kinetics in Se90Sb10-xAgx Glassy Alloys


Alloys of Se100-xSb10-xAgx (x=2, 4, 8) glassy system are obtained with rapid quenching. Calorimetric studies have been performed at different heating rates under non-isothermal conditions. Well defined endothermic and exothermic peaks are obtained at glass transition (Tg) and crystallization temperatures (Tc). In the present study, the glassy alloys are found to have double glass transition and crystallization temperatures. From the dependence of the glass transition temperature on the heating rate β, the activation energy of glass transition has been calculated on the basis of Moynihan and Kissinger models. The value of (Tc–Tg) and stability parameters have also been calculated for each composition for both the phases. Value of Eg is found to be decreased with increase in concentration of Ag. The values of (Tc-Tg) is highest for the sample with 8 at % of Ag. Activation energy of crystallization (Ec) has also been calculated using the well-known Kissinger’s relation, Matusita–Sakka theory and the method of Augis and Bennett. A good agreement has been found in all the three methods. The activation energy of crystallization is found to decrease with increasing concentration of Ag.