Influence of Prototype Undulation upon H- (Not U-) Ferroelectricity. Distinction between Amplitudinal Transition and Phase-Differential Transition

抄録

U- (or H-) ferroelectricity is ferroelectricity that should (or should not) vanish if the prototypic phase is brought from being undulated to homogeneity. This paper deals only with H-ferroelectricity. For simplicity the order parameter system is assumed to comprise only one real variable. Prototype undulation exerts certain influences upon H-ferroelectricity. As one of these influences, prototype undulation causes the following distinction for the paraelectric to ferroelectric transition. If the direction of prototype undulation is perpendicular to the ferroelectric direction, the transition is amplitudinal. If parallel, phase-differential. (In the case of homogeneous prototype, no such distinction exists; the transition is neither amplitudinal nor phase-differential.) A detailed theory on the distinction is given.