THE SIGNIFICANCE OF TEMPERATURE-DEPENDENT DISTRIBUTIONS OF ACTIVATION-ENERGIES

While the response to an electric field of many disordered systems can be accounted for by postulating that the system contains independent particles with transition rates having a distribution of energy barrie rs or activation energies, in order to account for the temperature dep endence of the experimental results it is often assumed that this dist ribution depends on temperature. In this paper, the question is examin ed of the minimum temperature dependence of the energies of the rates for the individual particles that is required to produce such temperat ure-dependent distributions for the system. This permits the clarifica tion of the meaning of a temperature-dependent distribution of activat ion energies, and also shows that standard techniques such as the meas urement of thermally stimulated depolarization currents often cannot d etermine whether or not such a distribution exists.