Calorimetric study on Ge23Se67Sb10-0.5CsCl glass

The mechanical behavior of Ge23Se67Sb10 glass can be improved by adding CsCl facilitating the nano-crystaline formation. Understanding the crystallization mechanism of chalcogenide glass can help in directing the subsequent annealing processing and tuning the microstructure and physical properties. In this work, 99.5Ge(23)Se(67)Sb(10)-0.5CsCl glass was prepared and its transformation kinetics was investigated under non-isothermal conditions with heating rate up to 400 K min(-1). Using Vogel-Fulcher-Tammann equation, the ideal glass transition temperature was determined as T (0g) = 434.1 K. Using the classical JMA theory, the average activation energy and average growth exponent were determined as 135.0 and 2.4 kJ mol(-1), while using the model considering impingements (MCI), the two parameters were determined as 120.9 and 3.2 kJ mol(-1), respectively. Compared to JMA theory, the MCI model can fit the transition curves better, and it shows that the growth mode of the present glass is between two-dimension and three-dimension. By comparing with the result of Ge23Se67Sb10 glass, it is found that addition of CsCl can reduce the growth dimension and activation energy during crystallization.