Structural relaxation of As2Se3 glass and viscosity of supercooled liquid

The evolution of As2Se3 glass volume below the glass transition temperature was measured by dilatometry under isothermal and non-isothermal conditions. The experimental data can be described by Tool-Narayanaswamy-Moynihan model for a single set of kinetic parameters: Delta h*/R = 38.3 kK, ln(A/s) = -79.21, x = 0.57, beta = 0.71. The value of Delta h*/R is close to the apparent activation energy of viscous flow that was found to be E-n/R = 38 +/- 1 kK. It is shown that the same set of kinetic parameters can be used for a description of previously reported enthalpy relaxation data. This suggests that the volume and enthalpy relaxation kinetics is comparable at least within the limit of experimental errors. (c) 2005 Elsevier B.V. All rights reserved.