The atomic structure of a planar defect with a (001) habit plane, in single crystals of the layered perovskite, was determined by means of high-resolution Z-contrast imaging. It was found that the defect formed a structure, with two Sr-Ta-O perovskite blocks connected by a metallic Sr2 plane, rather than a Bi2O2 layer as in the perfect crystal. This defect was expected to be an efficient hole trap.

Structure Determination of a Planar Defect in SrBi2Ta2O9. Y.Yan, M.M.Al-Jassim, Z.Xu, X.Lu, D.Viehland, M.Payne, S.J.Pennycook: Applied Physics Letters, 1999, 75[13], 1961-3