Crystal growth kinetics in Se87.5 Te10 Sn2.5 glass

The crystallization process of Se87.5 Te10 Sn2.5 glassy was studied by differential thermal analysis (DTA) technique under non-isothermal condition at various heating rates. The crystallization parameters were calculated using different models. The validity of the Johnson–Mehl–Avrami (JMA) model to describe the crystallization process for the studied composition was discussed. Results obtained by directly fitting the experimental DTA data to the calculated DTA curves indicate that the crystallization process of Se87.5 Te10 Sn2.5 glass cannot be satisfactorily described by the JMA model. On the other hand, kinetic parameters of both the peak crystallization temperature Tp and the glass transition temperature Tg are significantly influenced by the heating rate. Simulation results indicate that the Sestak–Berggren (SB) model is more suitable to describe the crystallization kinetics. The crystalline phases were identified by using X-ray diffraction technique (XRD) and scanning electron microscopy (SEM)

Crystallization study of Sn additive Se–Te chalcogenide alloys

Results of differential thermal analysis (DTA) under non-isothermal conditions of glasses Se90 − xTe10Snx (x = 0, 2.5, 5 and 7 at.%) are reported and discussed. The glass transition temperature (Tg), the onset crystallization temperature (Tc) and the peak temperature of crystallization (Tp) were found to be dependent on the compositions and the heating rate. Values of various kinetic parameters such as activation energy of glass transition (Eg), activation energy of crystallization (Ec), rate constant (Kp), Hurby number (Hr) and the order parameter (n) were determined. For the present systems, the results indicate that the rate of crystallization is related to thermal stability and glass forming ability (GFA). According to the Avrami exponent (n), the results show a one dimensional growth for the composition Se90Te10 and a three dimensional growth for the three other compositions. The crystalline phases resulting from DTA and (SEM) have been identified using X-ray diffraction