Tracer (18O) diffusion experiments and model calculations for the study of cation vacancy migration in oxide crystals were reported. The model took advantage of the electrostatic coupling forces between anion and cation defects that allow the evolution of the cation vacancy profile to be observed by anion tracer experiments. Applied to SrTiO3, the ambipolar diffusion of Sr vacancies with HA = 3.5eV was found to be the dominant re-equilibration mechanism of the cation sub-lattice. This result was in contrast to earlier studies proposing the formation of SrO intergrowth phases.

Observation of Vacancy Defect Migration in the Cation Sub-Lattice of Complex Oxides by 18O Tracer Experiments. R.Meyer, R.Waser, J.Helmbold, G.Borchardt: Physical Review Letters, 2003, 90[10], 105901 (4pp)