An X-Ray and Dielectric Study of the Phase Transition in PbFe1/2Nb1/2O3-PbCo1/2W1/2O3 Ceramics

Abstract

Phase analyses in the solid solution of (1 - chi) PbFe1/2Nb1/2O3-chi PbCo1/2W1/2O3 were conducted by dielectric properties, heat capacity and E-P hysteresis at chi = 0.1 intervals. Lattice constants and superlattice intensities were analysed by x-ray diffraction, and the temperature-composition phase diagrams were determined. The system was found to form a solid solution of perovskite structure throughout the entire composition range, but the nature of phase transitions changes from ferroelectric-paraelectric for 0 less than or equal to chi less than or equal to 0.5 to antiferroelectric-paraelectric for 0.6 less than or equal to chi less than or equal to 1.0. The transitions of ferroelectric-paraelectric and antiferroelectric-paraelectric for 0.2 less than or equal to chi less than or equal to 0.5 and for 0.6 less than or equal to chi less than or equal to 0.8, respectively, were diffuse, while those of the ferroelectric-paraelectric and the antiferroelectric-paraelectric for 0.0 less than or equal to chi less than or equal to 0.1 and 0.9 less than or equal to chi less than or equal to 1.0, respectively, were sharp.