On the New Eight-Pseudospin Model for Hydrogen-Bonded KH₂PO₄ Family

Abstract

The new eight pseudo-spin model recently introduced to discuss in a unified fashion the ferroelectric and antiferroelectric phase transitions in the hydrogen-bonded crystals of the KH₂PO₄ family is reviewed. The dielectric susceptibilities along the unique ferroelectric c-axis, and the a (b)-axis, perpendicular to the unique axis, are calculated. The application to the mixed crystals is suggested.

Keywords:

• Ferroelectrics
• antiferroelectrics
• eight-pseudospin model
• phase transition
• dielectric susceptibility
• KH₂PO₄(KDP)
• NH₄H₂PO₄(ADP)