Effect of Powder Characteristics on Microstructure and Properties in Alkoxide‐Prepared PZT Ceramics

The effects of coprecipitation parameters on agglomerate structure in PZT (53:47) powders prepared from butoxide precursors were studied. Results showed that differences in agglomerate structures developed during coprecipitation persisted throughout subsequent processing steps, and the resulting sintered densities and microstructures to be correlated with the agglomerate structures. Coprecipitation parameters which most significantly affected the powder characteristics included temperature, dilution, p H, and hydrolysis rate (controlled by H 2 O concentration). Such processing parameters as powder rinsing, calcination temperature, and spray drying conditions also significantly influenced the developed microstructures. For equivalent processing conditions, the most dense and uniform microstructures were developed with the softer (and smaller) agglomerate structures, achieved from an acid ( p H 3.7) medium of low (3–5 volume percent) solids content with rapid hydrolysis ( ∼ 32 ml H 2 O / min ) and low temperature rise (10° to 15°C). Measured dielectric constants on the sintered PZT samples were found, generally, to increase with average grain size.