Ferroelectricity in lead monohydrogen phosphate, PbHPO4, and the deuterated form, PbDPO4

Abstract

PbHPO4 and the deuterated form PbDPO4 are found to be ferroelectric at room temperature with space group Pc. Pyroelectric, dielectric and ferroelectric measurements as a function of temperature show the room temperature values of the spontaneous polarization Ps are 0.72 and 2.1 μC/cm2, for PbHPO4 and PbDPO4 respectively, and second order ferroelectric-paraelectric phase transitions occur at 37°C and 179°C, respectively. The ferroelectric behavior is discussed in terms of the crystal structure.