A comprehensive thermodynamic model has been developed to determine the reaction conditions favoring hydro‐thermal synthesis of lead titanate (PbTiO3). 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 PbTiO3 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 PbTiO3 has been obtained at temperatures ranging from 413 to 433 K using lead acetate or lead nitrate and commercial TiO2 powder. Also, PbTiO3 has been synthesized at lower temperatures (353 T 363 K) by using lead acetate and hydrous (reactive) TiO2 and calcining the obtained amorphous product.
|Original language||English (US)|
|Number of pages||11|
|Journal||Journal of the American Ceramic Society|
|State||Published - Oct 1993|
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry