Direct determination of grain boundary atomic structure in SrTiO{sub 3}

In the electroceramic SrTiO{sub 3} the grain boundary atomic structure governs a variety of electrical properties such as non-linear I-V characteristics. An understanding of this atomic structure-property relationship for individual grain boundaries requires a technique which probes both composition and chemical bonding on an atomic scale. Atomic structure models for tilt boundaries in SrTiO{sub 3} bicrystals have been determined directly from experimental data, by combining high-resolution Z-contrast imagine to locate the cation columns at the boundary, with simultaneous electron energy loss spectroscopy to examine light element coordination at atomic resolution. In this paper we compare and contrast the grain boundary structure models of symmetric and asymmetric boundaries in SrTiO{sub 3}