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

Chalcogenide glasses of (As₅₀Se₅₀)_100−xAg_x (0 ≤ x ≤ 25) were prepared using the melt quenching technique under non-isothermal conditions. Differential scanning calorimetry curves measured at different heating rates (5 ≤ β ≤ 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.