First Order Phase Transformation in Amorphous Ge25Se75 – xSbx Glasses

Non-isothermal Differential scanning calorimetry (DSC) technique was used to study the kinetics of first order phase transformation in Ge25Se75 – xSbx glasses. The X-ray diffraction (XRD) technique was employed to investigate the amorphous and crystalline phases in Ge25Se75 – xSbx glasses. From the heating rate dependences of crystallization temperature; the activation energy for crystallization and other kinetics parameters were derived. The temperature difference (Tc – Tg) and Tc is highest for the samples with 6 % of Sb. Hence, Ge25Se69Sb6 glass is most stable. The enthalpy released is found to be less for Ge25Se69Sb6 glass which further confirms its maximum stability. The activation energy of crystallization ( Ec) is found to vary with compositions indicating a structural change due to the addition of Sb. The crystallization data are interpreted in terms of recent analyses developed for non-isothermal conditions. The present investigation indicates that both the glass transition and the crystallization processes occur in a single stage.