Bulk ferroelectric domain nucleation in KTiOPO4 crystals

Ferroelectric domain inversion in KTiOPO4 crystals has been studied for two different states of these crystals: superionic (at room temperature), and dielectric (at low temperature, when the ion transport is frozen). The stru cture of the ferroelectric domain inverted at room temperature demonstrates a dramatic domain broadening due to a bulk domain nucleation. The observed effect is ascribed to highly mobile potassium ions that contribute to the minimization of the depolarizing field and the surface energy of domain wal ls of new domain nuclei. (C) 2001 American Institute of Physics.