Low temperature synthesis of stoichiometric and homogeneous lead zirconatetitanate powder by oxalate and hydroxide coprecipitation

A wet procedure to prepare stoichiometric and homogeneous PZT powder (Pb(Zr 0.52Ti0.48)O-3) is described. Starting reagents are tetra-n-butyl zirconate , titanate, and lead acetate. The synthesis is based upon the coprecipitati on of metal hydroxides Pb(OH)(2), ZrO(OH)(2), TiO(OH)(2) and lead oxalate P bC2O4 in the pH range 9-10. Monophasic and sub-micrometer-sized PZT powder was obtained by calcination of the mixture of hydroxides and oxalate at 700 degrees C. The study shows that highly tetragonal PZT phase appeared after heating at 500 degrees C only. No intermediate phase such as PbTiO3 was de tected. The presence of two different lead precursors in the precipitate-Pb (OH)(2) and PbC2O4-involved this low-temperature PZT formation without inte rmediate mixed oxide. Dense and compositionally homogenous PZT ceramics wer e obtained by sintering the calcined powder at 1200 degrees C. These sample s exhibited good dielectric and piezoelectric properties. (C) 1999 Elsevier Science Ltd.