Pb VOLATILIZATION EFFECT ON DIELECTRIC AND PIEZOELECTRIC PROPERTIES IN A Ta-DOPED PMN-PT CERAMIC THICK DISK

A thick ceramic disk of 0.7Pb(Mg_1/3(Nb_0.9Ta_0.1)_2/3)O₃-0.3PbTiO₃ (PMNT-PT) was prepared by columbite precursor method with PbO powder buffer surrounding the disk during the sintering process. The dielectric and piezoelectric properties and the microstructure of PMNT-PT samples cut from the different depths of the disk are studied. The phase purity is homogenous in the whole disk within our x-ray diffraction resolution. The dielectric constants, and the piezoelectric effect, d₃₃, vary with different samples. The samples cut from the middle parts of the disk have the higher d₃₃. It is believed that the sample processes, especially the Pb volatilization is responsible for these results.