On the effective medium model for particles with a complex structure

We consider a generalization of the effective medium approximation to the case of matrices containing macroscopically inhomogeneous particles with an arbitrary structure (cermet topology). The form of the result is determined to a considerable extent by the heuristic choice of effective cells used to estimate the field and induction values averaged over the volume. The simplest choice of a particle in an unperturbed field as a cell leads to the Maxwell–Garnett approximation, while the self-consistent effective medium approximation corresponds to the replacement of the unperturbed field by the mean field. As an example, we describe particles with a shell, as well as statistically anisotropic media with a single preferred direction.