Electrical Properties of PGO-Doped PNN-PZT Thick Films on Si Prepared by Screen Printing Method

Abstract

PNN-PZT piezoelectric thick films were prepared on Pt/YSZ/SiO₂/Si substrates by a screen printing method. 0 ∼ 3 wt% Pb₅Ge₃O₁₁ (PGO) or 1 wt% PbO was added to prepare dense PNN-PZT thick films at low firing temperature. Densification, microstructure and electrical properties were investigated in the Pb₅Ge₃O₁₁ or PbO-doped PNN-PZT thick films which were fired at 900°C. Pb₅Ge₃O₁₁ doping increased the average grain size and the density, and enhanced electrical properties of the PNN-PZT thick film. However, the electrical properties of the PNN-PNT thick film were not improved by PbO doping due to chemical reaction and inter-diffusion at the interface between the thick film and the bottom electrode. The 2 wt% Pb₅Ge₃O₁₁-doped PNN-PZT thick film had the densest microstructure and the best electrical properties; dielectric constant (ϵ_r) of 1431, remanent polarization (P_r) of 21.0 μ C/cm² and coercive electric field (E_c) of 22.7 kV/cm.

Keywords:

• Piezoelectric
• thick film
• PNN-PZT
• Pb5Ge3O11
• sintering aid

ACKNOWLEDGMENTS

This work was supported by grant No. R05-2003-000-11734-0 from the Basic Research Program of the Korea Science & Engineering Foundation.