The Influence of Evaporation of PbO in the Synthesis of PZT by the Spray Pyrolysis Method

Abstract

A lead(II) zirconium titanium trioxide (PZT) was prepared by a spray pyrolysis of a nitrate solution, and the influence of evaporation of PbO during the process of the formation of PZT was investigated. The yield of PZT decreased with an increase in the temperature of spray pyrolysis. For comparison, a barium zirconium titanium trioxide (BZT) was prepared by the spray pyrolysis of a nitrate solution. Contrary to the case of PZT, the yield of BZT increased with an increase in the temperature of spray pyrolysis. The se results indicate that the application of the spray pyrolysis to the preparation of PZT is not appropriate, because PbO evaporates from the particles during the pyrolysis.
Although the spray pyrolysis products consisted of PZT and other phases, the compositions of the products were almost the same as the feed solutions. When the product was fired at 1100°C, a nearly single phase of PZT was formed. The PZT synthesized by the spray pyrolysis, however, had a larger compositional fluctuation than that synthesized by a solid-solid reaction among PbO, ZrO₂ and TiO₂. The maximal dielectric constant near the Curie temperature of the sample decreased with an increase in the temperature of spray pyrolysis. PZT was also prepared by another method, viz., a combination of a spray pyrolysis and a solid-solid reaction. PZT synthesized by this method had no compositional fluctuation.