Kinetics based evidence for intermediate phase in Ge15Te85 − xInx chalcogenide glasses

This paper presents the thermal studies carried out using Differential Scanning Calorimetry on Ge15Te85 − xInx glasses (1 ≤ x ≤ 11) to find glass transition temperature, Tg and crystallization temperature, Tx. Further, the variation of Tg and Tx for different heating rates have been studied. The composition dependence of Tx, Tg and stability factor, ΔT have been investigated. The crystallization kinetics has been studied by a non-isothermal method; the activation energy of crystallization, Ex has been determined using Kissinger method whereas glass transition activation energy, Eg using Kissinger as well as Tool-Narayanaswami-Moynihan (TNM) methods for all the compositions. The results obtained reveal the opening of an intermediate phase, IP in the composition range 2 ≤ x ≤ 7. Tg, Tx and ΔT increases continuously across the IP region. The Ex exhibits a plateau and Eg follow a bell shaped curve in the IP region.