AC dielectric constant of insulator-conductor systems

The dielectric properties of insulator-conductor composite materials placed in a variable electromagnetic field were investigated. The case of a strong skin effect was considered. The skin effect results in the renormalization of the dielectric constant of conducting particles. As a consequence the frequency dependence of the effective dielectric constant of the system can considerably differ from the original ones. Two types of composite systems, characterized by the percolation threshold or not, were examined. The latter exhibits considerably lower values of effective dielectric constant (even in the case of high concentration of the conducting component), and shows potential for microwave applications and creation of artificial `dielectric ferromagnets´