Conductivity measurements were made of composites which consisted of a Cu+ ion conductor and a dispersed insulating oxide. A numerical model which assumed a simple topology, and an increased conductivity in narrow regions near to the heterophase boundaries, provided a satisfactory explanation for the experimental results; especially with regard to the concentration dependence of the conductivity. For strong wetting, as in the present composite, a linear relationship was found between conductivity and volume fraction within a certain range.

P.Knauth, J.M.Debierre, G.Albinet: Solid State Ionics, 1999, 121[1-4], 101-6