MODELIZATION OF ELECTRICAL INTERGRAIN CONTACTS AT HIGH-FREQUENCIES

A number of physical and physicochemical properties of granular materi als can be traced to the nature of the interfaces and contact between the grains, In this paper we deal more specifically with the electrica l resistance of the inter-granular contacts, More generally we will co nsider the frequency-dependent contact a.c. impedance. We propose a mo delling of the mesoscopic electrical contacts which can lead to a bett er understanding of some macroscopic properties of these materials, in particular the interaction with electromagnetic field. This modelling makes use of the percolation model and the representation of contacts by equivalent electrical circuits.