Preparation and properties of lead-based ferroelectric thin films

The crystalline properties of sol-gel derived lead-based ferroelectric thin films on several kinds of substrates were investigated. The polycrystalline lead zirconium titanate (PZT), lead lanthanum titanate (PLT) and PbTiO3 ferroelectric thin films, the highly oriented PbTiO3 ferroelectric thin films and the epitaxial growth PZT, PLT ferroelectric thin films with perovskite-type structure were prepared by the sol-gel method. Lead-based ferroelectric thin films had good ferroelectricity. The remanent polarization Pr and coercive field Ec of Pb(Zr0.5Ti0.5)O3 ceramic thin films at 1 kHz were 20 μC cm−2 and 40 kV cm−1 respectively. Pr and Ec of the PLT15 ceramic thin films at 1 kHz were 17 μC cm−2 and 46 kV cm−1 respectively. Pr and Ec of the PbTiO3 ceramic thin films at 50 Hz were 15 μC cm−2 and 80 kV cm−1 respectively. Lead-based ferroelectric thin films had good pyroelectricity. The pyroelectric coefficients y of the PLT5, PLT10, PLT15 and PbTiO3 ceramic thin films at room temperature were 3.37 × 10−8 C cm−2 K−1, 5.25 × 10−8 C cm−2 K−1, 7.10 × 10−8 C cm−2 K−1 and 2.9 × 10−8 C cm−2 K−1 respectively. The dielectric constants ϵγ of PLT and PbTiO3 ceramic thin films were about 200 and 150. The dielectric losses tan δ of PLT and PbTiO3 ceramic thin films were about 0.02 and 0.01 respectively.