Preparation and properties of lead-based ferroelectric thin films

Abstract

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 PbTiO 3 ferroelectric thin films, the highly oriented PbTiO 3 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 P r and coercive field E c of Pb(Zr 0.5Ti 0.5)O 3 ceramic thin films at 1 kHz were 20 μC cm −2 and 40 kV cm −1 respectively. P r and E c of the PLT15 ceramic thin films at 1 kHz were 17 μC cm −2 and 46 kV cm −1 respectively. P r and E c of the PbTiO 3 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 PbTiO 3 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 ϵ γ of PLT and PbTiO 3 ceramic thin films were about 200 and 150. The dielectric losses tan δ of PLT and PbTiO 3 ceramic thin films were about 0.02 and 0.01 respectively.