Modelling of the dielectric response of materials containing mobile charges

The authors report the preliminary results of computer simulations designed to model the response of a dielectric containing mobile charge to an applied alternating voltage. The models are more physically realistic versions of one proposed by F. Sterne and C. Weaver (J. Phys. C., vol.3, p.1736-46, 1970). It is shown that the assumptions made in the Sterne-Weaver model affect the calculated values of permittivity. Contrary to Sterne-Weaver, it is shown that it is not possible to approximate a system containing two mobile ionic species of opposite polarity by only allowing one of the species to migrate under the influence of the applied electric field; nor can diffusive effects be ignored as they can produce a major modification to the distribution of the ionic species. As the frequency of the applied electric field is increased the influence of the diffusive effects will become less marked