Synthesis of Lead Titanate: Thermodynamic Modeling and Experimental Verification

A comprehensive thermodynamic model has been developed to determine the reaction conditions favoring hydro‐thermal synthesis of lead titanate (PbTiO 3 ). The model combines standard‐state thermodynamic data for solid and aqueous species and an excess Gibbs energy model to account for the nonideality of the solution. The method has been used to generate phase stability diagrams that indicate the ranges of pH and reagent concentrations for which various species predominate in the system at a given temperature and pressure. Also, yield diagrams have been constructed that indicate the concentration, pH, and temperature conditions for which different yields of crystalline PbTiO 3 can be obtained. The stability and yield diagrams have been used to predict the optimum synthesis conditions (e.g., reagent concentrations, pH, and temperature). Subsequently, these predictions have been experimentally verified. As a result, phase‐pure perovskite PbTiO 3 has been obtained at temperatures ranging from 413 to 433 K using lead acetate or lead nitrate and commercial TiO 2 powder. Also, PbTiO 3 has been synthesized at lower temperatures (353 T 363 K) by using lead acetate and hydrous (reactive) TiO 2 and calcining the obtained amorphous product.