Atomistic simulation study of ⟨1 1 0⟩ dislocations in strontium titanate

The core structures of glide-dissociated screw and edge < 110 >{1 (1) over bar0} dislocations in strontium titanate are investigated by means of atomistic simulations. It is shown that for both dislocations the Sr, Ti and O sublattices follow different patterns of elastic displacements and that the partial dislocations have extended core structures. Dissociation distances in the range of experimental results are obtained, and a long-standing discrepancy between theoretical and experimental predictions of the anti-phase boundary energy is resolved. Studies of dislocations under applied load reveal marked difference in mobilities of the screw and edge dislocations that are consistent with experimental observations. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.