A theoretical and numerical framework was provided for the investigation of the interactions between domain walls and arrays of dislocations in ferroelectric single crystals. A phase-field approach was implemented in a non-linear finite element method to determine equilibrium solutions for the coupled electromechanical interactions between a domain wall and a dislocation array. The numerical simulations demonstrated the effect of the relative size and orientation of dislocations on 180° and 90° domain wall configurations. In addition, results for the pinning strength of dislocations in the case that domain walls move due the application of external electric field and shear stress were computed. The presented numerical results were compared with the findings reported for charged defects and it was shown that non-charged defects, such as dislocations, could also interact strongly with domain walls, and therefore affected the ferroelectric material behaviour.

Computational Modelling of Domain Wall Interactions with Dislocations in Ferroelectric Crystals. A.Kontsos, C.M.Landis: International Journal of Solids and Structures, 2009, 46[6], 1491-8