Orientation of the Ferroelectric Domain Wall in Triglycine Sulfate Crystals

Abstract

The domain wall energy as a function of wall orientation in triglycine sulfate (TGS) crystals has been calculated on the basis of the Zhirnov-type continuum theory. Contrary to the Fousek’s misleading conclusion [Japan. J. appl. Phys. 6 (1967) 950.], the isotropic treatment of the correlation-energy coefficient κ gives an inadequate result to explain the observed wall orientation which is nearly perpendicular to the crystallographic c axis. An anisotropy of κ has been reasonably introduced; a wall orientation consistent with the observations has been successfully brought about. The anisotropies of the dielectric, elastic and electrostrictive constants of TGS rather ineffectively contribute to the orientation of the domain walls.