Study of Glass-Transition Kinetics of Pb-Modified Se_{80}In_{20} System by Using Non-isothermal Differential Scanning Calorimetry

Glass-transition kinetics of $\mathrm{Se}_{80}\mathrm{In}_{20-\mathrm{x}}\mathrm{Pb}_{\mathrm{x}}$ ( $x =$ 0, 5, 10, and 15) chalcogenide glasses have been carried out at different heating rates by using differential scanning calorimeter (DSC) under the non-isothermal condition. The glass-transition temperature $T_{\mathrm{g}}$ and peak glass-transition temperature $T_{\mathrm{pg}}$ have been determined from DSC thermograms. The reduced glass temperature $T_{\mathrm{rg}}$ , total relaxation time $\tau _{T_{g}}$ thermal-stability parameters $K^{l}$ and $S$ , the activation energy of glass transition $E_{\mathrm{g}}$ , the fragility index $F_{\mathrm{i}}$ , and the average coordination number $\langle Z\rangle $ have been calculated on the basis of the experimental results. The temperature differences $(T_{\mathrm{c}}-T_{\mathrm{g}}), K_{\mathrm{gl}}, K^{l}, S$ , and $E_{\mathrm{g}}$ are found to be maxima for $\mathrm{Se}_{80}\mathrm{In}_{10}\mathrm{Pb}_{10}$ glass. This indicates that $\mathrm{Se}_{80}\mathrm{In}_{10}\mathrm{Pb}_{10}$ glass has the highest thermal stability and glass-forming ability in the investigated compositional range. These results could be explained on the basis of modification of the chemical bond formation due to incorporation of Pb in the Se–In glassy matrix.