Ferroelectricity in betaine phosphite

Abstract

Betaine phosphite, an addition compound of the amino acid betaine and phosphorous acid, can be grown in single crystal form from aqueous solutions. Structural, optical, dielectric, and caloric data of this new material are reported. At least two phase transitions are observed in (CH₃)₃NCH₂COO˙H₃PO₃. The lower one, around 216 K, leads to a ferroelectric phase with a spontaneous polarization of about 1.7 μC/cm².