Atomistic simulation study of 〈1 1 0〉 dislocations in strontium titanate

The core structures of glide-dissociated screw and edge 〈110〉{11¯0} 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.