SHAPES OF MOVING DOMAIN BOUNDARY AFFECTED BY EDGE DISLOCATION IN FERROELECTRIC CRYSTAL OF TRIGLYCINE SULFATE

Shapes of moving 180°-wall affected by stresses due to a dislocation were obtained for TGS crystals from calculations based on Nakamura's theory of domain growth. Anisotropic sidewise velocity, υ, of wall motion under the stress was determined on the assumption that υ depended on Τ through the wall energy density σ; the Τ dependence of σ was derived from the Zhirnov-type continuum theory. An edge component, rather than a screw component, of a dislocation which is parallel to the ferroelectric axis affects the value of σ. Under a low field the wall is caught in the dislocation, while under a high field it easily passes through the dislocation. The results are in qualitative agreement with experimental observations. © 1979, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.