A CONTINUUM PERCOLATION MODEL FOR DISPERSED IONIC CONDUCTORS

A continuum percolation model for heterogeneous mixtures of an ionic conducting solid salt with an insulating second phase is introduced. In this model, the insulating phase is represented by spherical random voids (the Swiss Cheese model) which are allowed to overlap and are randomly distributed in a conducting matrix (the solid salt). A characteristic feature of the model is the existence of a highly conducting spherical shell surrounding the voids, representing the internal interface between the oxide particle and the conducting salt. The relevance of the model for describing the observed effects of insulating particle size on the conductivity of dispersed ionic conductors is critically discussed.