Coexistence of toroidal and polar domains in ferroelectric systems: A strategy for switching ferroelectric vortex

Phase field simulations have been conducted to investigate the vortex domain structure in ferroelectric nanodots epitaxially grown on ferroelectric nanofilm. It is found that the nanodot region has great impact on the domain evolution of the whole system. At suitable conditions (e.g., geometry, size, temperature, external strain, and electric field), the nanodot adopts a vortex domain pattern while the nanofilm maintains a polar domain. Interestingly, the vortex domain pattern of the nanodot can be switched by controlling the direction of the adjacent polar domain. Our study indicates an alternative strategy for controlling the chirality of vortex domain structure in nano-ferroelectrics. (C) 2014 AIP Publishing LLC.