Modelling of Maxwell–Wagner induced polarisation amplitude for clayey materials

Abstract

Induced polarisation exists for a wide variety of heterogeneous media in which conductive particles are embedded in a resistive coating. This phenomenon can be explained either by reversible chemical “reactive” processes or by the Maxwell–Wagner (M–W) interfacial polarisation effect. Modelling of the amplitude of the later effect for both isotropic and platelet like polarisable cells, shows that it can adequately explain the results obtained in clayey materials. In order to investigate the role of platelet flatness, we firstly consider the isolated spherical water drop model, then the platelet model, and finally take into account the influence of coupling between cells. It is found that the platelet flatness coefficient has a greater influence on M–W relative permittivity than on its electrical conductivity, which suggests that effective permittivity can be a useful indicator of texture.