Kinetics of Phase Transformations and Thermal Stability of Se 58 Ge 42-x Pb x (x = 15, 18 & 20) Glasses

This paper presents the results of kinetic studies of glass transition and crystallization in Se58Ge42-xPbx (x = 15, 18 & 20) glasses using differential scanning calorimetry (DSC). It has been observed that these glassy systems exhibit single glass transition and double crystallization on heating. The crystalline phases have been identified by annealing the samples at temperatures intermediate between the first and second crystallization peaks. The structural characterization of the as-prepared and annealed glassy alloy has been done through X-ray diffraction (XRD). The activation energy for glass transition as well as crystallization region has been calculated using various theoretical models. In addition, the effect of annealing on various kinetic parameters of transformations has been studied. On the basis of the experimental results on phase transformations in these glasses, thermal stability of the samples under investigation has been ascertained. It was found that the thermal stability is profoundly affected by annealing since the glass transition as well as crystallization temperatures are strongly influenced by annealing the samples. The phase transformation study reveals that the thermal stability of the samples increases with the increase in lead content in the samples.