INTERFACIAL CONDUCTION IN IONICALLY CONDUCTING 2-PHASE MATERIALS - CALCULATIONS USING THE GRAIN CONSOLIDATION MODEL

We have used the grain consolidation model to study the ionic conducti vity in different two-phase composite systems where interfacial conduc tivity is assumed to be causing a conductivity enhancement. The model predicts results that are qualitatively similar to experimental data, displaying sharp ''knees'' in the composition dependence. We have mode led materials consisting of grains in a host background where the grai n size is either constant or Varying with concentration. The model can explain even unusual behavior such as the existence of both a maximum and a minimum in conductivity at intermediate compositions. To achiev e this we had to assume that the grains become smaller as their volume fraction increases.