Atomistic simulations of symmetrical low-angle [100] (01l) tilt boundaries in SrTiO3

The structural properties of symmetrical low-angle [100] (01l) tilt grain boundaries in the perovskite oxide SrTiO3 were investigated by empirical pair potentials and energy minimisation techniques. Thirteen interfaces with misorientation angles varying between theta = 3 degrees and theta = 22.6 degrees were studied in both stoichiometric and oxygen deficient forms. Examination of the relaxed simulation cells indicated that all the studied grain boundaries consisted of some combination of two different types of dislocation core. The structures of the two types of dislocation core remain unchanged at low misorientation angles but become increasingly distorted at the highest angles examined. Simple rules were derived to predict the type, arrangement and alignment of the dislocations at a given interface. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.