Composites of 0.3Pb(Mg1/3Nb2/3)O3-0.7Pb( Zr0.52Ti0.48)O3 prepared by a sol-gel method

PMN-PZT electroceramic composites were fabricated from PMN powder + PZT powder (P-P processing) and PMN powder + PZT solution (P-S processing) using a sol-gel process. The particle sizes of PMN-PZT powder prepared by P-S processing were more than 3 times greater (more than 1 micron) compared with that of P-P processed powder (0.3 micron). The grain size, density, and dielectric constant of PMN-PZT ceramics prepared by P-S processing were larger than those of P-P processed samples. The specimen sintered at 1230 C by P-P processing exhibited similar properties to that sintered at 1170 C by P-S processing. Ceramics prepared from a PMN core enclosed in a PZT shell using a polymerised solution mixed at molecular level (powder + solution processing) showed better structural and dielectric properties compared to samples processed with mixed sol-gel powders. 20 refs.