Effect of Excess PbO on Phase Formation, Microstructure and Dielectric Properties of (Pb0.975Ba 0.025)ZrO3 Ceramics

Polycrystalline samples of (Pb0.975Ba0.025)ZrO3 (PBZ2.5). were prepared by a mixed oxide, solid-state reaction method. Excess PbO (1,3, 5 or 10 wt.%) was introduced prior to powder calcination to compensate for any PbO that may have been lost from the samples due to volatilsation during heat treatments. The phase structure was analyzed by XRD.A pure PBZ2.5 phase was observed in all of the ceramic samples. Microstructurally, excess PbO produced an increase in average grain size, from ~ 0.5 μm for no excess to ~0.8 μm for excess PbO. Dielectric constant-temperature plots showed a maximum peak value of 8070, for the 1 wt. % sample which was also the densest sample