Modelling thermal activation of <1Â 1Â 0>{1Â 1Â 0} slip at low temperature in SrTiO3

The core structure of <1 1 0>{1 1 0} screw dislocations has been modelled in SrTiO3 with the Peierls-Nabarro-Galerkin method. This model relies on γ-surfaces calculated ab initio for the {1 0 0} and {1 1 0} planes. The <1 1 0>{1 1 0} screw dislocation has a planar core and its Peierls friction is 350 MPa. The kink-pair theory is applied to model thermal activation of dislocation glide over the Peierls barrier. This model is found to reproduce satisfactorily the critical resolved shear stresses observed experimentally below 1000 K.