A screw dislocation was studied using negative spherical aberration-imaging in a spherical aberration-corrected transmission electron microscope. The core structure of the dislocation was resolved atomically with respect to both cation and O columns by including the central core area. The dislocation core was characterized by a helical distortion of the lattice planes which led in particular, to azimuthally elongated image dots which were associated with individual atomic columns close to the core center. The atomic coordination in the dislocation core was identified, and a high density of atom vacancies was revealed for a Ti-O column at the core.

Atom Vacancies at a Screw Dislocation Core in SrTiO3. C.L.Jia, L.Houben, K.Urban: Philosophical Magazine Letters, 2006, 86[11], 683-90