CRYSTALLIZATION KINETICS OF OVERLAPPING PHASES IN SE0.6GE0.2SB0.2 CHALCOGENIDE GLASS

From the DSC study, the Se0.6Ge0.2Sb0.2 chalcogenide glass has two amorphous phases and its crystallization takes place in two overlapping processes. By annealing as-prepared samples at 244°C for 2 h, the second phase can be observed. From X-ray diffraction measurements, the first phase identified is Sb2Se3 and the second phase is GeSe2. From the variation of the volume fraction of crystals with temperature, the crystallization mechanism for Sb2Se3 and GeSe2 phases are two dimensional and surface processes, respectively. The glass transition activation energy (Et) and the crystallization activation energy (Ec ) of Sb2Se3 phase were calculated by different methods to be 234.4±4.0 and 228.5±13.2 kJ/mol, respectively. For the GeSe2 phase the corresponding values were 271.4±3.8 and 245.2±18.9 kJ/mol, respectively. © 1990.