Transient Nucleation in Ge–Sb–S Thin Films

The crystal nucleation behavior and kinetics in Ge1.8Sb36.8S61.4 thin films were studied using optical microscopy coupled with a computer-controlled heating stage. The single-stage in situ heat treatment method was chosen for the study of nucleation. In-situ experiments were performed in the temperature range of 236–295 °C. The time evolution of the number of nuclei at various temperatures revealed transient behavior at low nucleation times. The transient nucleation data were described using the Shneidman equation to get values of steady-state nucleation rate, induction period, and time-lag of nucleation for the studied temperatures. On the basis of nucleation experiments, the temperature dependence of crystal–liquid surface energy and decoupling of nucleation rate and viscosity was assessed. The nucleation rate data obtained from microscopy measurements were discussed in terms of classical nucleation theory. It was found that the nucleation curve with the maximum at 288 °C and previously published growth curve with maximum at 309 °C overlap significantly.