On the iso-conversional analysis of the activation energy of amorphous-crystalline transition in nano-crystalline Se-Te-In-Pb chalcogenide glasses

The present paper examines the fluctuations in activation energy of amorphous-crystalline phase transition of Se79-xTe15In6Pbx (x = 0, 1, 2, 4, 6, 8 and 10) chalcogenide glasses using computational iso-conversional analysis for the data obtained under non-isothermal conditions using differential scanning calorimetric technique at four different heating rates; 5, 10, 15 and 20 K/min. This study examines how the activation energy of crystallization (Ec) varies with the degree of conversion (χ) and temperature (T) using an algorithm developed in Python named as HPU-B-MASS. The Python algorithm incorporates iso-conversional methods; Kissinger-Akahira-Sunose (KAS), Ozawa-Flynn-Wall (OFW), Tang & Chen and Starink methods to analyze the variation of with both χ and T. It is found that Ec is not constant but varies with χ as well as T. The iso-conversional analysis of the investigated glasses indicates that the assumption of constant Ec is not appropriate. Ec obtained for the investigated alloys from different methods are different. This difference can be attributed to the fact that these methods are based on approximations involved in obtaining the final equation of different formalisms. Furthermore, our findings suggest an increased propensity for crystallization in glasses with Pb content as compared to the parent ternary alloy.