Pyroelectric effect and freezing out of domain structure in betaine arsenate

Abstract

This work reports some results concerning the study of pyroelectric effect in Betaine Arsenate ((CH₃)₃ NCH₂ COO.H₃ As O₄). The pyroelectric coefficient along the crystallographic c-axis reveals two anomalies localized in the temperature range of 110–120 K. The existence of these two anomalies is confirmed by an experimental study of dielectric constant and dielectric loss in the same samples. We interpret the upper anomaly as that between a paraelectric and a mixed phase, i.e. a ferroelectric and structural glass and the lower one as a freezing temperature where the domain wall mobility is frozen out.