Shape Dependence of the Properties of Ferroelectric Crystals

Abstract

On the basis of elementary molecular field theory, one can predict the transition temperature and Curie constant for a ferroelectric material in terms of the spontaneous polarization. In such a calculation, if migration of free charges did not occur, it is evident that the internal electric field produced by surface depolarization charges should play an important role. Experimental measurements of the transition temperature and Curie constant as a function of sample shape have been performed for several materials and the results are presented for triglycine sulfate. No shape dependence was observed which can be explained by the migration of free charges in the material.