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

Autor: M.S. El-Bana, Neeraj Mehta, S.S. Fouad, Amit Kumar
Rok vydání: 2017
Předmět:
Zdroj: Journal of Thermal Analysis and Calorimetry. 131:2491-2501
ISSN: 1588-2926
1388-6150
Popis: 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 $$T_{\text{g}}$$ , onset crystallization temperature $$T_{\text{o}}$$ , peak crystallization temperature $$T_{\text{c}}$$ ) and static melting temperature $$T_{\text{m}}$$ of the quaternary glassy series have been determined using their non-isothermal DSC curves. These temperatures were utilized to calculate the thermal stability $$S$$ and the Hruby parameter $$H_{\text{R}}$$ for the studied glasses. Both the activation energy of glass transition $$E_{\text{t}}$$ and the activation energy of crystallization $$E_{\text{c}}$$ for all compositions were evaluated using the well-known Kissinger's relation and the method of Augis–Bennett. Values of the fragility index $$m$$ and the crystallization rate factor $$K_{\text{p}}$$ were estimated using the activation energy values $$E_{\text{t}}$$ and $$E_{\text{c}}$$ , 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.
Databáze: OpenAIRE
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