ELECTRICAL PROPERTIES OF PGO-DOPED PNN-PZT THICK FILMS ON SI PREPARED BY SCREEN PRINTING METHOD

摘要

PNN-PZT piezoelectric thick films were prepared on Pt/YSZ/SiO_2/Si substrates by a screen printing method. 0 approx 3 wt percent Pb_5Ge_3O_(11)(PGO) or 1 wt percent PbO was added to prepare dense PNN-PZT thick films at low firing temperature. Densification, microstructure and electrical properties were investigated in the Pb_5G_e3O_(11) or PbO-doped PNN-PZT thick films which were fired at 900 deg C. Pb_5Ge_3O_(11) 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 percent Pb_5Ge_3O_(11)-doped PNN-PZT thick film had the densest microstructure and the best electrical properties; dielectric constant (epsilon_r) of 1431, remanent polarization (P_r) of 21.0 /iC/cm~2 and coercive electric field (E_c) of 22.7 kV/cm.