Effect of Composition and Size of Crystallite on Crystal Phase in Lead Barium Titanate

Lead titanate, barium titanate, and lead barium titanate powders (>99.9% pure), the particle size of which varied from 0.03 to 0.15 μm depending on the calcination temperature and the composition, was prepared from barium lead titanyl oxalate, which was previously prepared by reacting high‐purity ammonium titanyl oxalate with barium and lead acetate. The critical crystallite size of BaTiO3 powder from the cubic to the tetragonal phase is around 1 μm. Pb0.3Ba0.7TiO3 powder with an average size of 0.057 μm showed the tetragonal phase.