Ag-Sb-Te system for phase change optical data storage

For phase change optical data storage, several chalcogenide-based materials have been reported and are expected to replace the conventional magnetic disk. In the present work, preparation and characterization of the chalcogenide alloy Ag (x) - Sb (2 (1-x)) - Te (3) ((1-x)) with different composition (x = 0.16, 0.18 and 0.20) has been presented. Samples were prepared using melt quenching technique and the films were grown by thermal evaporation system. The crystallization process of Ag- Sb- Te material was studied using differential thermal analysis (DTA) and Optical analysis (Transmittance and reflectance) respectively. The films were studied for both cases: before and after annealing. The Differential thermal analysis curves were recorded for different compositions and Glass transition temperature (T (g)), crystallization temperature (T (c)) and melting temperature (T-m) have been obtained. It may also be concluded that T (g) / T (m) ratio is closer to required condition for the phase change optical data storage material. Thermal and optical analysis shows that the Ag - Sb- Te material is a potential candidate for phase change optical data storage. The optimized composition has also been obtained.