Probing 3‐D Structural Distortions and Coordination Changes at SrTiO 3 Grain Boundaries Using Electron Energy Loss Spectroscopy

Critical to a fundamental understanding of the structureproperty relationships in ceramics is the ability to address the key issues of like‐ion repulsion, partial occupancy, and composition at defect cores. Here, multiple scattering theory is used to produce a symmetry‐projected, site‐specific, density of states for defect structures observed experimentally in a SrTiO 3 high‐angle tilt grain boundary. The real space atomic clusters used in multiple scattering calculations do not rely heavily on symmetry, thus permitting the structural origins of particular features to be readily identified in low‐symmetry systems. Results are compared directly with experimental electron energy loss spectra and give strong evidence for partial occupied columns of atoms at specific interface cores and the persistence of bulklike atomic correlations at the grain boundary.