Activation energy of Se2Ge0.2Sb0.8 chalcogenide glass by differential scanning calorimetry

Results of differential scanning calorimetry (DSC) at different heating rates on Se2Ge0.2Sb0.8 chalcogenide glass are reported and discussed. As the heating rate (alpha) changed, also the glass transition temperature (T-g) and onset temperature of crystallization (T-c) changed. As the value of the transition activation energy E(t) changed, the crystallization fraction (chi), heat flow (Delta q) and the crystallization peak temperature (T-p) also changed. The value of the effective activation energy of crystallization E(c) was calculated by means of six different methods. The Se2Ge0.2Sb0.8 chalcogenide glass has two crystallization mechanisms, a one-dimensional and an other surface crystallization growth. The average value of E(t) for Se2Ge0.2Sb0.8 is equal to 194.95+/-3.9 kJ . mol(-1) and the average value of E(c) is equal to 164+/-3.3 kJ . mol(-1).