Activation energy spectra in relaxation: crossover and reversibility

Abstract

Relaxation in glasses is analysed in terms of spectra of activation energies. Isothermal annealing and “crossover” experiments are used. New data from measurements of Curie temperature and data for refractive index published by others are analysed. Over a wide range a simple approximation to the activation energy spectra is satisfactory but the step function approximation to the annealing function is inadequate. Presentation of data in terms of a function incorporating isothermal annealing time and temperature, kT ln νo t is advantageous.