Switching mechanism of polarization vortex in single-crystal ferroelectric nanodots

The polarization switching in a single-crystal ferroelectric tetragonal nanodot subjected to curled electric fields is investigated by a phase field model. The simulation results show that the switching of polarization vortex in the tetragonal nanodot does not begin from the location with the highest energy density, which is different from those of ferroelectric nanotubes and ferroelectric cylindrical nanodots. It is found that the vortex switching begins from the dot corners with the lowest elastic energy density, which implies that the elastic constraint as well as the geometry play an important role on the switching of polarization vortex in ferroelectric nanostructures. (C) 2010 American Institute of Physics. [doi:10.1063/1.3515847]