Thermal analysis of cadmium addition on the glass transition and crystallization kinetics of Se-Te-Sn glassy network

Calorimetric measurements have been performed in quaternary glassy system Se78-xTe20Sn2Cdx (x = 0, 2, 4, and 6) to study the thermally induced glass transition and crystallization phenomena. The characteristics kinetic temperatures (glass transition temperature , onset crystallization temperature , peak crystallization temperature ) and static melting temperature of the quaternary glassy series have been determined using their non-isothermal DSC curves. These temperatures were utilized to calculate the thermal stability and the Hruby parameter for the studied glasses. Both the activation energy of glass transition and the activation energy of crystallization for all compositions were evaluated using the well-known Kissinger's relation and the method of Augis-Bennett. Values of the fragility index and the crystallization rate factor were estimated using the activation energy values and , respectively. The compositional dependence of the above-mentioned parameters was discussed on the basis of rigidity models and according to the formation of iono-covalent bonds when our glassy Se-Te-Sn system is doped with a heavy element as Cd.