Effect of Ag addition on crystallization in As2Se3 glasses

Differential scanning calorimetry (DSC) behaviours of glassy As2Se3 containing Ag up to 5 at % were measured at various heating rates. The effect of addition of Ag on crystallization of glassy As2Se3 was investigated. The glass transition temperature decreased with increasing Ag content. Crystallization kinetics were analysed on the basis of the two-step process model, where crystal growth takes place after nucleation. For non-doped As2Se3 two-dimensional growth of crystal was predominant, while for Ag-doped ones three-dimensional growth was very likely. It was supposed for all glassy Ag-doped samples that crystal nuclei exist, though micro-crystallites were not observed on X-ray diffraction traces. The activation energy for crystallization and the glass-forming tendency decreased by the addition of Ag.