Structural relaxation in amorphous solids studied by thermal analysis methods

Structural relaxation for simple and more complex thermal histories is desc ribed by a phenomenological model based on a non-exponential relaxation fun ction, the reduced-time concept and the nonlinear structural contribution t o the relaxation time. The history, development of experimental techniques and data analysis is described. It is shown that the volume and enthalpy re laxation response can conveniently be compared on the basis of a fictive re laxation rate, R-f. A simple equation relating R-f and the parameters of th e phenomenological model is given. The calculated data for moderate departu res from equilibrium are in good agreement with our experiments and data pr eviously reported in the literature.