Processing and characterization of Ca, Ce and Na ion doped lead titanates

Precursor powders of both alkaline-earth- and rare-earth-doped lead-titanate-based ceramics have been synthesized using an attrition milling process. The influence of dopants and powder processing parameters on the sintering, microstructure, and dielectric and piezoelectric properties of the products is discussed. Compared with pure lead titanate, modified lead titanates having alkaline-earth and rare-earth oxides as major dopants are shown to exhibit lower crystal tetragonality. Most of the materials studied can be sintered to high densities (~95% or higher). SEM (scanning electron microscope) studies indicate composition-dependent fracture behavior. The materials demonstrate a fairly narrow temperature range for densification. A mere 100°C variation from the optimum sintering temperatures appears to have adverse effects on both the sample density and the microstructure. Both the dielectric and the piezoelectric properties in these materials are strongly influenced by the sample composition