Dielectric Dispersions

It is shown that perfect insulators must have perpendicular intersections of the Cole-Cole diagram with the ¿ axis. This perpendicularity is found for several distributions of relaxation times, but not for some empirically derived approximations. The Cole-Cole diagrams for these distributions are discussed and compared. The intersections with the ¿ axis occur at zero and infinite frequency. The introduction of dc conductivity in the perfect dielectric makes it a pseudo-insulator. At high frequencies these materials have a Cole-Cole diagram similar to that of a perfect dielectric, but in the low-frequency range large deviations occur and no intersection with the real axis can occur at zero frequency.