Crystallization kinetics of homogeneously precipitated lead zirconate titanate using urea: Comparison with the conventional ammonia precipitated sample

Abstract

Ultrafine, PbZr0.53Ti0.47O3 powder was synthesized by homogeneous precipitation of metal ions in aqueous solution using urea. The results obtained from different characterization methods were compared with those obtained from the conventional precipitation method using ammonia in terms of crystallization, homogeneity, and microstructure. The as-dried precipitate converted to the single-phase crystalline lead zirconate titanate powder when calcined at 550 °C and above. The calcined powder showed smaller particle size, minimum agglomeration, and uniform shape. The growth of the particles was very little at higher temperatures. Powdered samples that precipitated using urea crystallized directly to rhombohedral lead zirconate titanate, without any intermediate pyrochlore phase formation. The NH3-precipitated powder converted to rhombohedral lead zirconate titanate via metastable pyrochlore and it showed phase segregation upon annealing at higher temperatures. The reaction kinetics has been studied by x-ray diffraction, differential thermal analysis, and differential scanning calorimetry.