Pb(Mg_(1/3)Nb_(2/3))O_3-PbTiO_3 thick films from mechanochemically synthesized powder

摘要

The phase composition, microstructure and electrical properties of thick-film structures based on 0.65Pb(Mg_(1/3)Nb_(2/3))O_3-0.35PbTiO_3 (PMN-PT) were studied. PMN-PT powder with 2 mol percent of excess PbO was prepared by high-energy milling from the constituent oxides. A high yield of perovskite PMN-PT with nano-sized particles was obtained after the synthesis. A paste was prepared from the obtained powder, screen printed on platinised alumina substrates and sintered at 850, 900 and 950 deg C. Single-phase PMN-PT thick-film structures without any pyrochlore phase were obtained after the sintering. The dense PMN-PT layers had good dielectric, piezoelectric and ferroelectric properties. The relative dielectric permittivity of 4100 and the peak value of 41,000 for the film sintered at 950 deg C compare well with bulk ceramics sintered at much higher temperatures. The d_(33) value of the film was 170 pC/N. The obtained values for the dielectric properties demonstrate the good chemical homogeneity of material synthesized by high-energy milling.