Impedance Spectra for a 2-D Conductor-Insulator Composite by Computer Simulation

Using a computational methodology, ac impedance spectra of macroscopic mixtures of conducting and insulating hard spheres which have random or regular arrangements of the components are studied. These simulations can be used to calculate the ac electrical properties of a multi-component composite using a personal computer. It is shown in this study that ac impedance spectra are sensitive functions of the filling fraction and the geometrical arrangement of the components, and especially, the impedance spectra of the composite show the abnormal arc originated from the isolated clusters in the composite. From the simulated impedance patterns of the isolated clusters with various length, the abnormal arcs are shown to appear more distinctly when the elongated clusters are arranged along the preferred current line.