The atomic structure of a SrTiO3 dislocation was revealed directly by phase-retrieval electron microscopy. In particular, atomic columns of light O were observed simultaneously with the columns of considerably heavier Sr and Ti. A distinct structural modification of the O octahedra at the dislocation core as well as a significant non-stoichiometry, including a deficiency of O, were observed. Deviations from the bulk chemical concentration were quantified column by column by means of structure modeling and quantum-mechanical simulations of the electron scattering process.

Atomic-Scale Analysis of the Oxygen Configuration at a SrTiO3 Dislocation Core. C.L.Jia, A.Thust, K.Urban: Physical Review Letters, 2005, 95[22], 225506