Preparation and dielectric properties by sol-gel derived PMN-PT powder andceramic

A relaxer ferroelectric material, 0.85Pb(Mg1/3Nb2/3)O-3-0.15PbTiO(3) with a pyrochlore-free phase, was prepared by using sol-gel method. The metal alk oxide Nb(OC2H5)(5) and Mg(OC2H5)(2) are substituted by Nb(OH)(5) and Mg(NO3 )(2). During the processing the gel first converted to pyrochlore phase at a calcination temperature of 500 degrees C followed by the formation of pur e perovskite phase at 1100 degrees C. The grain size and the dielectric con stant increased with an increase in the sintering temperature. The chemical composition analysis shows starting material shift to a higher PT-content (PT similar to 17%) for the final material. (C) 2000 Elsevier Science S.A. All rights reserved.