Structure determination of a planar defect in SrBi2Ta2O9

The atomic structure of a planar defect with a (001) habit plane in single crystal layered perovskite ${\mathrm{SrBi}}_{\mathrm{2}}{\mathrm{Ta}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{9}}$ is determined by high-resolution Z-contrast imaging. We found that the defect forms a structure, with two Sr–Ta–O perovskite blocks connected by a metallic ${\mathrm{Sr}}_{\mathrm{2}}$ plane, rather than a ${\mathrm{Bi}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{2}}$ layer as in the perfect crystal. This defect is expected to be an efficient hole trap and may have important implications for the electronic properties and the ferroelectric response of the ${\mathrm{SrBi}}_{\mathrm{2}}{\mathrm{Ta}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{9}}$ material.