From representative volume element of interacting particles to the extraction of their effective properties

Abstract

The main concern of this investigation was the relation between the representative volume element of the scattered flux from 2D random agglomerates, composed of sub-wavelength interacting particles, and the extraction of their effective electromagnetic properties. Using a constant ratio between agglomerates radius and wavelength, behaviors of the scattered flux mean value and standard deviation were studied as a function of the agglomerate surface, in the case of relevant particle permittivities. Using the mean or standard deviation functions, two criteria for homogenization were derived. Compared to the extraction of the effective refractive index, both criteria failed to predict the minimal surface needed for homogenization, questioning the existence of a link between the accuracy of the scattered flux evaluation and homogenization. However, it is shown that when no surface-plasmon resonances are excited, a single minimal representative surface for homogenization can be defined.