Determination of optimal experimental conditions for the preparation of lead zirconate titanate via sol-precipitate process by applying statistical methods

A fractional factorial design was implemented to optimize the experimental conditions for the preparation of lead zirconate titanate (PZT) from acetate precursors. The effects of such preparatory conditions as the molar ratio of acetic acid to metal alkoxide, the water to alkoxide ratio, the pH value, reaction temperature and the stirring speed, were systematically studied by using a Taguchi orthogonal array design. Results indicated that the molar ratio of acetic acid to metal alkoxides and the reaction temperature were the key variables influencing the average particle size of the powders obtained. By combining the optimal setting of these two influential processing variables, a fine powder with a particle size of ≈2200 Å was obtained. Fourier transfer infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) were used to investigate the effects of the chelation on the rate of formation of the precursor and PZT powder. The rates of hydrolysis and polycondensation of the acetate precursors were slow because of the chelation of a high ratio of acetic acid with the alkoxide. The particle size of the obtained PZT powder was small and a homogeneous distribution resulted.