Anisotropic domain structure of KTiOPO4 crystals

Highly anisotropic ferroelectric domain structure is observed in KTiOPO4 (K TP) crystals reversed by low electric field. The applied Miller-Weinreich m odel for sidewise motion of domain walls indicates that this anisotropy res ults from the peculiarities of KTP crystal lattice. The domain nuclei of do zen nanometer size, imaged by atomic force microscopy method, demonstrate r egular hexagonal forms. The orientation of domain walls of the elementary n uclei coincides with the orientation of the facets of macroscopic KTP cryst als. The observed strong domain elongation along one principal crystal axis allows us to improve tailoring of ferroelectric domain engineered structur es for nonlinear optical converters. (C) 2001 American Institute of Physics .