The effect of Nb doping on dielectric and ferroelectric properties of PZT thin films prepared by solution deposition

Niobium (Nb)-doped lead zirconate titanate thin films (PNZT) were produced by solution deposition with nominal compositions, Pb(1-0.5x)(Zr0.53Ti0.47)(1-x)NbxO3 where x = 0.00-0.07. The effects of sintering temperature, sintering time, variation of thickness in the films and change of niobium content were investigated with regard to phase development, microstructure, and ferroelectric and dielectric characteristics. The best results were obtained in double-layered films (390 nm) sintered at 600 degrees C for 1 h. Optimum doping level was found in 1% Nb-doped films. For 1% Nb-doped [Pb-0.995(Zr0.53Ti0.47)(0.99)Nb0.01O3] films, remanent polarization (P-r) of 35.8 mu C/cm(2) and coercive field (E-c) of 75.7 kV/cm have been obtained. The maximum dielectric constant was achieved in 1% Nb-doped films which was 689. Ferroelectric and dielectric properties decreased at higher Nb doping levels because of the changes in the grain size and perovskite lattice parameters. (C) 2008 Elsevier Ltd. All rights reserved.