Studies of periodic ferroelectric domains in KTiOPO4 using high-resolutionx-ray scattering and diffraction imaging

A periodically domain-inverted KTiOPO4 crystal, in which inverted ferroelec tric domains were produced by electric-field poling, has been studied using high-resolution x-ray scattering and diffraction imaging techniques. The d egree of perfection of domain inversion as well as the periodic structure h as been revealed in high-spatial-resolution images, and the periodic contra st is shown to arise largely from lattice distortions produced in the poled regions. The q(parallel to) dependence of intensity scattered from the dom ain-inverted structure can be described by a two-component line shape, one with a sharp nearly-pure-Gaussian line, the other with a broad pseudo-voigt -function profile. A high-angular-resolution method has been combined to el ucidate the origin of the two-component profile. The diffuse scattering of the crystal truncation rod along q(perpendicular to) is observed to follow a power law q(perpendicular to)(-gamma) with gamma similar to 2.29 +/- 0.03 after poling compared with an average value of 2.05 +/- 0.03 before poling . Discussions of the electric-field poling and its consequence for the doma in-inverted structure are presented in terms of the results of x-ray measur ements. [S0163-1829(99)09921-X].