Interfacial polarization in composite materials with spherical fillers: characteristic frequencies and scaling laws

The dielectric properties of composite materials consisting of a host matrix filled with spherical particles are investigated as a function of frequency by means of numerical calculations. Two different cases are analyzed: (a) composites with a conductive matrix and insulating fillers and (b) composites with an insulating matrix and conductive fillers. In both situations, dielectric dispersions due to interfacial polarization effects are observed in the dielectric spectra. In the present contribution, the characteristic frequencies of interfacial polarization effects are systematically analyzed in dependence on the volume fraction of the spherical fillers and on the conductivity values of the composite phases. The resulting scaling laws are discussed in detail.