The behavior of ABO3/A’BO3 perovskite diffusion couples was investigated theoretically and experimentally. A theoretical model of the form of Darken’s analysis was developed which established criteria for the occurrence of the Kirkendall effect in such oxides. It was demonstrated that the lattice velocity should exhibit a maximum value at some dopant concentration that increased the vacancy concentration on the A-A’ sub-lattice in diffusion couples. The interdiffusion coefficients in La2/3TiO3-doped couples with BaTiO3 were measured at 1573K. On the basis of porosity formation, the lattice velocity in these couples was deduced to exhibit a maximum at a certain La2/3TiO3 concentration; in agreement with theoretical predictions.

S.Gopalan, A.V.Virkar: Journal of the American Ceramic Society, 1995, 78[4], 993-8