Effects of Pb concentration on phase, microstructure and electrical properties of Bi3.25La0.75Ti3O12 ceramics

In this work, effects of Pb-doping concentration on phase, microstructure and electrical properties of bismuth lead lanthanum titanate (Bi1−xPbx)3.25La0.75Ti3O12 or BPLT ceramics when x = 0, 0.01, 0.03, 0.05, 0.07, 0.09 and 0.1 were investigated. Phase analysis by X-ray diffraction indicated the existence of orthorhombic phase for all BPLT powders and ceramics. Microstructural investigation using scanning electron microscope showed that all ceramics composed mainly of plate-like grains. An increase in PbO doping content reduced not only diameter and thickness of the grains but also density of the ceramics. Electrical conductivity was found to decrease while dielectric constant increased with Pb-doping concentration. Small reduction of remanent polarization and coercive field was observed in Pb-doped samples.

► We prepared bismuth lead lanthanum titanate ceramics by a solid state mixed-oxide method.
► The optimum sintering temperature was found to be 1150 °C.
► BPLT ceramic was identified by X-ray diffraction method to possess an orthorhombic structure.
► All samples shows plate-like morphology with varying grain size and orientation.
► Increasing Pb-doping content tended to decrease electrical conductivity values.