Devitrification of Bi- and Ga-containing germanium-based chalcogenide glasses

Novel BixGay(GeSe4)50-(x+y)/2(GeTe4)50-(x+y)/2 glasses are proposed as perspective materials, having potential to combine thermo-electric effect, rare earth solubility, different types of conductivity and topological insulating behavior in one medium. Thermal stability and non-isothermal crystallization kinetics of these materials are studied by differential scanning calorimetry, X-ray diffraction and Raman scattering techniques. Crystallization of at least five different phases is assumed due to the fit of experimental DSC curves. The Dietzel criterion of glass stability is determined and the activation energy for each crystallization process is calculated. The applicability of Johnson-Mehl-Avrami (JMA) equation to describe the crystallization kinetics is verified in these glasses.