Dielectric and ferroelectric properties of PMN–PT–PZ ceramics prepared via combustion technique

Abstract

The fabrication of 0·53Pb (Mg1/3Nb2/3)O3–0·37PbTiO3–0·10PbZrO3 (PMN–PT–PZ) ferroelectric ceramics using the combustion technique and the effects of firing conditions on the phase structure, microstructure and electrical properties of the powders and ceramics were studied. Glycine was used as a fuel to reduce the reaction temperature. It was found that a single perovskite phase of PMN–PT–PZ powders was obtained from the sample calcined at 900°C for 2 h. The conventional technique uses two steps in the calcination process. The use of glycine in the combustion technique reduced the process to one step. The morphology of the PMN–PT–PZ powders showed an almost spherical shape and the average particle size increased from 0·12 to 2·51 μm when the calcination temperature was increased from 700 to 1000°C. The pure PMN–PT–PZ ceramics exhibited coexistant phases of the rhombohedral and the tetragonal perovskite phase in the samples sintered at a temperature lower than 1100°C. A second phase of pyrochlore was found in the samples sintered at temperatures higher than 1150°C. The PMN-PT-PZ ceramics sintered at 1100°C for 2 h exhibited the highest density, highest linear shrinkage and highest dielectric constant at Tc of 7·72 g cm−3, 16·13% and 18337 respectively. The densest PMN-PT-PZ ceramic exhibited good ferroelectric properties of (using an electric field at 30 kV cm−1) Pr = 26·9 μC cm−2 and Ec = 4·5 kV cm−1.