A thermal analysis study of melt-quenched Zn5Se95 chalcogenide glass

Abstract

Thermal analysis of chalcogenide glass similar to other materials is of great importance in order to increase the knowledge about its phase transitions, thermal stability, etc. The current study reports on the thermal kinetics of melt-quenched Zn5Se95 chalcogenide glass using differential thermal analysis (DTA) techniques under non-isothermal conditions. The glass-forming ability (GFA) and the relation between the glass transition and onset crystallization temperatures are found to show a linear behavior. In addition, Moynihan et al. Kissinger’s, and other approaches of Johnson-Mehl-Avrami utilized to determine the activation energy of the amorphous-crystalline and glass transition. It is found that the glass transition process cannot be concluded in terms of single activation energy, and that variation with the extent of conversion was analyzed using various iso-conventional methods. Therefore, the observed change of the activation energy throughout the glass transition reveals that the transition from amorphous to the supercooled liquid phase of Zn5Se95 glass is a complex process. The crystallization process at different heating rates is simulated using the Málek method, and Šesták–Berggren SB(M,N) model, in which the SB model show fairly good matching with the experimental DTA data. Moreover; the fragility index is a measure of the GFA of Zn5Se95 chalcogenide glass, which has been estimated using the glass transitions and activation energy values. We have found that the fragility index of Zn5Se95 glass values in between ∼13 and 30, depending on the heating rate, revealing that the synthesized glass is a strong liquid with excellent GFA.