A study was made of why the formation of a space charge layer caused an ionic conductivity enhancement in composite electrolytes. A rigorous analytical solution was presented for the formation of the space charge layer. The formation of the layer was assumed to arise from the formation of a thin amorphous phase by defect reactions at the interface between the second phase and the matrix. The electrical potential distribution, the ionic defect distributions, and the average densities of ionic defects in the space charge layer, were obtained in analytical form. An enormous enhancement of the density of mobile ionic defects in the space charge layer was derived for the first time in analytical form.

S.Jiang, J.B.Wagner: Journal of the Physics and Chemistry of Solids, 1995, 56[8], 1101-11