Effect of Ag addition on crystallization kinetics and thermal stability of As-Se chalcogenide glasses

Chalcogenide glasses of (As50Se50)(100-x)Ag-x (0 ae x ae 25) were prepared using the melt quenching technique under non-isothermal conditions. Differential scanning calorimetry curves measured at different heating rates (5 ae beta ae 40 K min(-1)) are used to characterize the as-quenched samples. The thermal stability was monitored through the calculation of the temperature difference T (c) - T (g), stability parameter S and crystallization rate factor K (p). The glass-forming ability (GFA) was investigated on the basis of Hurby parameter H (r) which is a strong indicator of GFA. In addition, the activation energy of glass transition E (t), activation energy of crystallization E (c) and Avrami exponent n of the studied compositions were determined. The mechanism of crystallization was found to be a combination of two- and three-dimensional crystal growth.