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: Δh*/R = 38.3 kK, ln(A/s) = −79.21, x = 0.57, β = 0.71. The value of Δh*/R is close to the apparent activation energy of viscous flow that was found to be Eη/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.