LOW-TEMPERATURE SINTERING OF LEAD-BASED PIEZOELECTRIC CERAMICS

The low-temperature sintering of leadbased piezoelectric ceramics has been studied. The sintering temperature of lead zirconate titanate (PZT) ceramics could be reduced from ≈ 1250° to ≈ 960°C by the addition of a small amount of the lower-melting frit, B2O3-Bi 203-CdO. It exhibited the following dielectric and piezoelectric properties: Kp=0.52 to 0.58, Qm=1000, ΕT33/Ε0=800 to 1000, tan δ=50 × 10-4, p = 7.56 to 7.64 g/cm3 · Ceramics with the aid of suitable dopants (CdO, SiO2, and excess PbO) in the Pb-(Ni1/3Nb2/3)03-PZT family could be sintered at 860° to 900°C. For these materials, Kp=0.56 to 0.61, Qm = 1000, ΕT33/Ε0=1500 to 2000, tan δ≤ 50 × 10-4, ρ=7.80 to8.03 g/cm 3· The microstructure, sintering mechanism, and the effects of various impure additions have been analyzed by means of scanning electron microscopy, scanning transmission electron microscopy, electron probe microanalysis, and X-ray photoelectron spectroscopy.