The blocking effect of boundaries in bicrystals, upon the chemical diffusion of O, was monitored in situ. The optical technique which was used permitted the precise recording of spatial profiles as a function of time. The low-symmetry boundary (near S = 13) exhibited a marked chemical resistance, which was reflected by a distinct jump in the diffusion profiles, while the highly symmetrical S = 3 boundary exhibited no measurable influence. The effects could be quantitatively explained by Schottky barriers, and the diffusion profiles could be precisely modelled by assuming the space-charge potential to be the only unknown parameter.

In situ Monitoring and Quantitative Analysis of Oxygen Diffusion through Schottky Barriers in SrTiO3 Bicrystals. M.Leonhardt, J.Jamnik, J.Maier: Electrochemical and Solid State Letters, 1999, 2[7], 333-5