Abstract: 0.3Pb(Ni_1/3Nb_2/3)O₃-0.7Pb(Zr,Ti)O₃ (PNN-PZT) thick films (10-40μm) were prepared by electrophoretic deposition method on Al₂O₃/Pt plates and Pt metallic foils. The effect of pH value on the stability of PNN-PZT suspensions was studied by measuring the zeta potential. The relationship among the deposition voltage, time and the quality of PNN-PZT films were investigated. When the pH value is in the range of 3.5-5.5, the suspension with the 2wt% PEG is stable. When the deposited voltage and time are 21V and 5min, respectively, the PNN-PZT thick films deposited on the Pt foil are uniform and free of crack. After sintering at 1200℃ for 30min, the PNN-PZT films with high density are obtained. The PNNPZT thick films show the high ferroelectric and dielectric properties with the remnant polarization of 20.8μC/cm² and the loss tangent of about 3.2% at 1 kHz. And the frequency dependences of the dielectric spectra of the PNN-PZT thick films show the relaxor property. The piezoelectric constant calculated from the SV curve tested using the SPM is 67pm/V.

Key words: PNN-PZT thick film, electrophoretic deposition, dielectric property, polarization hysteresis loop