Pressure-Temperature Phase Diagram of Ca₂Ba(C₂H₅COO)₆

Abstract

The pressure-temperature phase diagram of Ca₂Ba(C₂H₅COO)₆ was drawn in a pressure range of p≤7 kbar and a temperature range of −100°C≤T≤+200°C from dielectric constant measurements. Four pressure-induced phases IV, V, VI, VII were detected besides atmospheric pressure phases of I, II, III. The phase boundaries and the order of transitions between them were determined. At the transition from the high pressure IV phase to V phase, a pronounced dielectric constant peak was observed. The height of the peak decreases with increasing pressure. Ferroelectric hysteresis loops were not observed around the temperature at the peak of dielectric constant.