Crystallization kinetics and composition dependence of some physical properties of Sn-Sb-Bi-Se chalcogenide glasses

Chalcogenide alloys of Sn10Sb20−xBixSe70 (0⩽x⩽8) system were prepared by the melt quenching technique. Thin films were prepared on well-cleaned glass substrates by the thermal evaporation technique. The X-ray diffractogram for x=0 reveals the amorphous nature as no sharp peak is observed but the sample with x=4 shows sharp peaks. The glass transition, crystallization, melting temperatures and glass-forming tendency of the amorphous samples were determined from differential scanning calorimetric measurements. The glass transition activation energies and the crystallization activation energies were determined using the Kissinger method. Optical transmission and reflection spectra of thin films were obtained in the range 400-2500 nm. The conductivity activation energy and optical gap initially increases with increasing Bi concentration (for x=2) and then decreases sharply for higher Bi content. The values of the band tailing parameter and the pre-exponential factor are also reported and discussed.