The effect of polydispersity on the dielectric properties of composite materials

We undertake a systematic numerical investigation on how does /spl epsiv//sub eff/ depend on the width of the particle size distribution. We have simulated the effective permittivity of composites consisting of well separated conductive spherical inclusions in an insulating matrix. Results are presented in a broad range of filling factors and size distribution widths. They reveal a sensitive dependence of the dielectric response on the size distribution of the inclusions. The numerical results are compared with well-established theoretical models. We also emphasise on some salient aspects of the simulation method.