Calorimetric studies on Ge23Se67Sb10-0.5%RbI glass

Understanding the crystallization mechanism of chalcogenide glass can help in directing the subsequent annealing processing, thus tuning the microstructures and physical properties. In this work, the transformation kinetics of Ge23Se67Sb10-0.5%RbI was investigated under non-isothermal conditions. From VFT equation, the ideal glass transition temperature was determined as T0g = 427.74 K. The fragility index m was estimated to be 64.74, indicating a relatively fragile liquid. From the classical JMA theory, the activation energy was determined as 222.9 kJ/mol, growth index was 1.26, while from the model considering the impingement modes(MCI) activation energy was determined as 90.99 kJ/mol and growth index was 1.38, which indicated that the growth mode of crystallization of the present glass was between one dimension and two dimension. The result shows that addition of RbI can reduce the growth dimension and activation energy.