DIFFERENTIAL SCANNING CALORIMETRY STUDY OF STRUCTURAL RELAXATION OF GE-DOPED SE85TE15 GLASSES

Accurate measurements of the apparent specific heat below and through the glass transition in slowly cooled Ge-x(Se85Te15)(100_x) glasses (x = 0, 2 and 10) were performed using differential scanning calorimeter . The enthalpy released by the glasses when annealed near the glass tr ansition was deduced. The kinetics of coordination short range orderin g (CSRO), structural relaxation and the glass transition were studied by continual heating as well as by isothermal methods of thermal analy sis. The activation energies of structural relaxation Delta E were ob served to be similar for all samples, as was the qualitative correlati on of their absolute values which ranged from 120-143 kJ (g atom)(-1) for CSRO processes at T-a=T-g-60 K, to 217 kJ (g atom)(-1) for glass t ransformation processes in glass having x = 10, as determined by vario us methods of kinetic analysis (Kissinger, Moynihan, activation energy spectrum and distribution of non-linear relaxation models). This may be explained by assuming first-order kinetics and a wide spectrum of r elaxation times.