Two-layer dielectrics behaviour in the electric field

The authors present experimental results of the breakdown strength for two-layer dielectrics under high electric field. The relation between the breakdown strength (E_b) and the boundary position (ξ) between the layers is anomalous in character. Similar results for the dissipation factor tanδ in low and high field were obtained. We suppose that the changes discovered in E_b and tanδ with changing ξ are probably caused by the peculiarities of the relaxation polarization, due to the existence of an abrupt step in both the permittivity and conductivity at the boundary between the dielectric layers