Dislocation Dependence of Cationic Diffusion in SrTiO 3

Cation self‐diffusion was measured in single‐crystal strontium titanate. Nonhomogeneous diffusion kinetics were observed and were interpreted by the Fisher model. The composite diffusion coefficient, P , of the Fisher model is shown to have a dependence on dislocation density, ρ, in single crystals at 1875°C given by: image for strontium, and image for titanium. It has previously been shown that oxygen ions have enhanced diffusivities in dislocation pipes; therefore, in SrTiO 3 all ions exhibit enhanced dislocation diffusion. Based on an assumed maximum value for lattice diffusion, the temperature dependence of strontium dislocation pipe diffusion is given by: image where h 2 is the dislocation core area.