An-Najah Staff

Glasses belonging to the Ge–S–Ag system were investigated by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The DSC results show that the glass transition temperature (T_g), the onset crystallization temperature (T_c) as well as the temperature interval (T_c -— T_g) decrease with increasing amount of Ag content in the glass. The decrease of (T_c — T_g) indicates that the thermal stability of the glass decreases. The X-ray structure factors obtained on glasses with 5, 10 and 15 at% Ag have a first sharp diffraction peak (FSDP), characteristic of intermediate range order, whose intensity decreases gradually with increasing Ag content in the glass up to 15 at%. For the glasses with Ag content ≥20 at%, this FSDP is totally absent, These results may be taken as prima facie evidence that the decrease or the absence of intermediate range order in the glass decrease its thermal stability.