Elastic Anomaly of the Antiferroelectric CsH₃(SeO₃)₂ Single Crystal

Abstract

We have measured elastic compliance constants s a , s b and s c for the elongation along the three crystallographic axes of the antiferroelectric CsH 3 (SeO 3 ) 2 single crystal (triclinic, P \bar1) by the composite resonator method. All the constants s a , s b and s c have been found to exhibit large anomaly at the transition point (-128°C) and small anomaly near the temperature above it. This small anomaly suggests the existence of a new phase.