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

A wet procedure to prepare stoichiometric and homogeneous PZT powder (Pb(Zr0.52Ti0.48)O3) is described. Starting reagents are tetra-n-butyl zirconate, titanate, and lead acetate. The synthesis is based upon the coprecipitation of metal hydroxides Pb(OH)2, ZrO(OH)2, TiO(OH)2 and lead oxalate PbC2O4 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 C. The study shows that highly tetragonal PZT phase appeared after heating at 500 C only. No intermediate phase such as PbTiO3 was detected. The presence of two different lead precursors in the precipitate--Pb(OH)2 and PbC2O4--involved this low-temperature PZT formation without intermediate mixed oxide. Dense and compositionally homogeneous PZT ceramics were obtained by sintering the calcined powder at 1200 C. These samples exhibited good dielectric and piezoelectric properties