Crystallization kinetics of some Ge-Sb-Se glasses

Abstract

The crystallization kinetics of alloys in the Ge-Sb-Se system was investigated by means of differential thermal analysis, differential scanning calorimetry and X-ray diffraction. The calorimetric results obtained both for isothermal and continuous heating experiments were successfully interpreted with the same set of kinetic parameters. The Johnson-Mehl-Avrami-Erofe'ev equation with a rate constant following the Arrhenius behaviour gives the best fit to the experimental data. The values obtained for the effective activation energy increase from 75 to 229 kJ/mol with Sb content, except for pure selenium (81 kJ/mol). The pre-exponentlal factor of the rate constant increases at the same time from 1×10 6 to 1×10 16 s −1, except for pure selenium (4×10 6). The kinetic exponent ranges between 1.2. and 2.5 without any clear trend against composition. Some kind of compensation effect occurs that may be attributed to the primary crystallization of Sb 2Se 3 in most of the glasses.