The Effect of Excess PbO on Crystal Structure and Microstructure of (Pb0.925Ba0.075)TiO3 Ceramics
In this work, we studied the effect of excess PbO doping on lead barium titanate [(Pb0.925Ba0.075)TiO3; (PBT)] ceramic. PBT was prepared via a mixed oxide method with various PbO levels (-3, 0, 1, 3, 5 and 10 wt.%). The excess PbO was added to compensate the loss from evaporation during calcination and sintering at 800 oC and 1150 oC. It was found that lead barium titanate powders indexed in a tetragonal structure. Impurity phases of lead oxide (PbO), titanium oxide (TiO), and lead dioxide (PbO2) were detected in the calcined powders with higher than 1 wt% of excess PbO. The impurity phase was not obtained in any ceramic samples. The c/a ratios decreased with an increasing excess of PbO in both calcined powders and sintered pellets. The average particle size and the average grain size of the PBT increased with the increase of PbO. The shrinkage plots showed a maximum peak for the 1 wt.% sample which was also the most dense sample.
T. Bongkarn and R. Sumang, "The Effect of Excess PbO on Crystal Structure and Microstructure of (Pb0.925Ba0.075)TiO3 Ceramics", Advanced Materials Research, Vols. 55-57, pp. 177-180, 2008