Dielectric and Magnetic Properties of Pb(Fe1/2Ta1/2)O3

Abstract

Single crystals of Pb(Fe_1/2Ta_1/2)O₃ were grown from ternary melts with excess PbO. The crystals, having cubic perovskite structure at room temperature, undergo a ferroelectric phase transition at about 243°K, changing to rhombohedral structure. The dielectric constant passes through a maximum of nearly 9500 at 1 KHz. The spontaneous polarization along [100] direction is ca 28 µC/cm² at liquid nitrogen temperature. A magnetic anomaly at about 180°K is related to the onset of antiferromgnetic ordering.