Thermal stability and crystallization kinetics of Er-doped Ge–Sb–Se chalcogenide: a DSC study.

Amorphous materials specifically chalcogenide glasses (Se, Te, and Sb alloys) are promising materials for fabrication of different solid-state devices and their characteristics can further be improved by doping with rare-earth element. Current study deals with phase transformation, thermal stability, and crystallization kinetics of Er-doped quaternary chalcogenide system which were synthesized using melt quenching technique. In this study, Ge17Sb8Se75−xErx (x = 0, 0.4, 0.8, and 1.0) alloy has been examined from differential scanning calorimetry data wherein the stability and kinetics is studied at variable heating rates. As a standard procedure, non-isothermal conditions were used throughout the kinetic and crystallization studies for understanding the variation in glass transition temperature, melting temperature, thermal stability factor, activation energy of glass transition, and crystallization wherein besides the role of chalcogen element, the doping concentration of rare-earth Er is also understood. Furthermore, devitrification resistance was also analyzed based on activation energy for crystallization. The synthesized Er-doped GeSbSe system shows an increase in transition temperature, melting temperature, thermal stability, and glass-forming ability when the concentration of Er and heating rate increases as compared to the pure alloy. Furthermore, decrease in the activation energy has been observed for Er-doped quaternary chalcogenide system. These observations indicate the potential of Er-GeSbSe chalcogenide glass as phase change memory material and other applications which needs high thermal stability. [ABSTRACT FROM AUTHOR]