An experimental study on the effective dielectric constant of heterogeneous media

An effective dielectric constant of heterogeneous layers, in which BaTiO₃ particles are dispersed in a polymer mix, has been studied experimentally. When the experimental values of an effective dielectric constant for the BaTiO₃-polymer layers were plotted against the volume fraction of BaTiO₃, it was found that the experimental values were inside the Hashin-Shtrikman bounds and fit the van Beek theory. Changes in the effective dielectric constant for the Cu-particle-glycerinum system associated with the sedimentation of the Cu particles were also examined. The results obtained confirmed that the effective dielectric constant of a heterogeneous system changes, depending on the phase configuration, even at a constant volume fraction of each phase