Phase-field modeling of domain structure of confined nanoferroelectrics.

The results of phase-field simulation of domain structures (DSs) in ferroelectric nanorods of different shapes and sizes are presented. It is shown that equilibrium DSs consist of an electrostatically compatible circuit of 180 degrees and 90 degrees domains. A DS in a thin rod contains 90 degrees cubic elastic domains. The trend to minimize the residual stress and the stray field results in the formation of crater-shaped sets of closed circuits of 90 degrees domains, which can be mechanically incompatible but able to maintain electrostatic compatibility during the evolution under an applied electric field.