LOW-TEMPERATURE SYNTHESIS OF ULTRAFINE PB(ZR,TI)O-3 POWDER BY SOL-GELCOMBUSTION

Lead zirconate titanate powders are derived from a novel aqueous-based citrate-nitrate/oxynitrate sol-gel combustion process. Aqueous soluti ons of metal nitrates or oxynitrates are transformed into gels with ci tric acid under heating. The received gels undergo a self-propagating combustion reaction on heating to 180 degrees C and subsequently yield voluminous ashes. These ashes form single phase perovskite Pb(Zr0.53T i0.47)O-3 powder with a specific surface area of 8 m(2)/g upon calcina tion at 550 degrees C. The ashes show a homogeneous distribution of le ad, zirconium, and titanium ions which guarantees short diffusion path s in solid state formation of PZT perovskite. The redox behavior of th e gels was studied with the help of DTA experiments. Powders are chara cterized in terms of XRD, SEM, and EDX analysis.