Phase-pure perovskite lead titanate with various morphologies has been synthesized by a hydrothermal method at 150 deg C. Particle shapes include cubic, tabular, and aggregated platelike shapes. The feed stock concentration greatly influences particle morphology of the hydrothermally derived PbTiO_3. At a concentration of 0.05 M, the tabular particles form while cubic particles are produced at 0.l M. Aggregated plateletlike particles are synthesized at 0.l25 M. It was observed that both tabular and cubic particles directly precipitate from the coprecipitated precursor gel. In contrast, the plateletlike shaped intermediate phase appears during the initial stage of reaction at 0. l25 M and in situ transforms into perovskite PbTiO_3 during further hydrothermal treatment. The intermediate phase preserves its particle shape during transformation and, acting as a template, gives rise to the final tabular PbTiO_3 particles. It is demonstrated that only base reagents such KOH and NaOH, which provide a highly basic condition (i.e., pH > l4), promote transformation of the coprecipitated gel into the perovskite PbTiO_3. A Hancock and Sharp kinetic analysis in conjunction with microstructural evidence suggests that the formation mechanism is dissolution and recrystallization in which the degree of supersaturation plays an important role in dictating the crystallographic particle phase and morphology of the particles. An experimentally consturcted solubility diagram indicates that an excess lead condition is necessary to compensate for loss of lead species and to increase supersaturatio
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