CONCENTRATION-DEPENDENCE OF THE ELECTRICA L-CONDUCTIVITY OF COMPOSITES AT A HIGH-FREQUENCY PLATEAU

A model describing the concentration dependence of electrical conducti vity in composites containing conducting fillers in the region of high -frequency plateau was advanced. Theory and experimental evidence show ed that, at a high-frequency plateau, the conductivity of composite ma terials was independent of their structure. The relationships were obt ained, which allowed the estimation of the parameters of contacts betw een filler particles and the description of concentration-frequency de pendences of electrical conductivity and dielectric permittivity in a wide range of variations of frequency and filler content in terms of t he RC-circuit model. In the case of composites, microwave dielectric m easurements may be used to study the interface.