It was recalled that dislocation core structures in complex minerals relevant to the Earth's mantle had recently been determined by using the Peierls-Nabarro model. In this approach, the original Peierls-Nabarro model was coupled with first-principles calculations of generalized stacking fault. In order to test the reliability of such calculations, a study was made here of the dislocation core properties in a perovskite-structured material, SrTiO3, for which a lot of experimental information was available. Four different slip systems were investigated in SrTiO3: <100>{010}, <100>{011}, <110>{001}, and <110>{11¯0}. The latter exhibited a lower lattice friction due to core spreading, and the next easiest slip system was found to be <100>{010}. It was shown that the present results (dislocation core spreading and Peierls stress values) were in perfect agreement with experiment (transmission electron microscopy model of core structure and mechanical properties), providing an interesting validation of the Peierls-Nabarro model for complex materials.

Modeling Dislocation Cores in SrTiO3 using the Peierls-Nabarro Model. D.Ferré, P.Carrez, P.Cordier: Physical Review B, 2008, 77[1], 014106 (7pp)