Nonisothermal crystallisation kinetics of amorphous selenium prepared by high-energy ball milling: A comparison with the melt-quenching and thin-film techniques

Differential,scanning calorimetry (DSC) studies were performed under nonisothermal conditions at various heating rates for glassy Se made by high-energy ball milling. Comparisons were made between the ball-milling technique and the melt-quenching and thin-film techniques. Well-defined endothermic and exothermic peaks were observed at the glass-transition temperature, T-g, and the onset temperature of crystallisation, T-c. The isoconversional method of Vyazovkin was used to determine the variation in the activation energy for crystallisation with temperature, E-alpha(T). The value of E-alpha(T) was dependent on the sample preparation method. The thermal stability of the Se glasses was evaluated by calculation of the temperature difference (T-c - T-g) and the S-parameter. In addition, the glass-forming ability was estimated by the criteria of reduced glass-transition temperature, T-rg, and the Hruby number, H-R. The structures of the Se samples that resulted from the DSC analysis were identified using an X-ray diffractometer. The glasses formed using the thin film technique were the most stable. (C) 2012 Elsevier B.V. All rights reserved.