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ZnO-based ceramic films, with thickness close to 2–4 μm, were deposited on Au/Si substrates by novel sol-gel process. The precursors were fabricated by dispersing doped-ZnO ceramic nano-powders into the sols, which were prepared by dissolving zinc acetate dihydrate into 2-methoxyethanol and stabilized by diethanolamine and glacial acetic acid and doped with a concentrated solution of bismuth nitrate, phenylstibonic acid, cobalt nitrate, manganese acetate and chromium nitrate. The doped-ZnO ceramic nano-powders were prepared by sol-gel processing through dried and calcined in air at 150 and 800 °C, respectively. The films were prepared by the spin coating method with the substrate spinning rates of 2000–3000 rpm. After each deposition, the films were heat-treated in air at 350–400 °C for 10 min. After ten to 20 layers, the films were annealed in air at 650–800 °C for 2 h. The films have been characterized by X-ray diffraction and scanning electron microscopy. The nonlinear V–I characteristics of the films for use as varistors were studied by transistor characteristics testing instrument. The nonlinear voltage was 2–10 V, the nonlinear coefficient ( α ) was 3–22. The highest nonlinearity coefficient with nonlinear voltage of 4 V could be achieved at 750 °C by the films with a thickness of 2 μm.

Lead zirconate titanate (Pb (\( \left( {Zr_{0.53} Ti_{0.47} } \right)O_3 \), PZT) ferroelectric films 2–60 μm in thickness have been successfully fabricated on Pt-coated oxidized Si substrates \( \left( {Pt/Ti/SiO_2 /Si} \right) \) by a new sol-gel-based process. The films are a 0-3 ceramic–ceramic composite formed by dispersing ceramic powders in a sol-gel solution. The precursor solution for spin coating was prepared from lead acetate, tetrabutyl titanate, and zirconium nitrate. The microstructure and morphology of the prepared PZT thick films were investigated via X-ray diffractometry (XRD) and scanning electron microscopy techniques. XRD analysis shows that the thick films possess single-phase perovskite-type structure, no pyrochlore phase exists in thick films, and SEM micrographs suggest that the PZT thick films were uniform, dense, and crack free. A dielectric constant of 860, loss tangent of 0.03, remanent polarization of \( 25\mu Ccm^{ - 2} \), and a coercive field of \( 40kVcm^{ - 1} \) were measured on 50 μm thick films.

Epitaxially grown and polycrystalline PbTiO3 (PT), (Pb, La)TiO3 (PLT) and Pb(Zr, Ti)O3 (PZT) thin films with thicknesses from 1 to 2 μm have been prepared on Pt/Ti/SiO2/Si substrates by means of a sol-gel spin-coating technique. The ferroelectric thin films have good crystallization behavior, excellent dielectric and pyroelectric properties. The pyroelectric coefficients of PT, PLT and PZT thin films are 2.9×10−8 c/cm2·k, (3.37–5.25)×10−8 c/cm2·k and 6.10×10−8 c/cm2·k, respectively. The figures of merit for voltage responsivity of PT, PLT and PZT thin films are 0.60×10−10 C cm/J, (0.59–0.78)×10−10 C cm/J and 0.63×10−10 C cm/J, respectively. The current responsivity of these films are 9.0×10−9 C cm/J, (10.5–16.0)×10−9 C cm/J and 19.1×10−9 C cm/J, and the detectivity are 0.74×10−8 C cm/J, (0.79–1.13)×10−8 C cm/J and 0.83×10−8 C cm/J, respectively.

Crack-free and homogeneous compact ceramic and epitaxial lead zirconate titanate (PZT) ferroelectric thin films with perovskite structure have been prepared by sol—gel processing. Tetrabutyl titanate, lead acetate and zirconium nitrate are used as raw materials. Glacial acetic acid is used as a catalyst. Ethylene glycol monoethyl ether is used as a solvent. The annealing temperatures of the thin films are 600–900 °C. The values of the remanent polarization P r and the coercive field E c of the Pb(Zr 0.5 Ti 0.5 )O 3 ceramic thin films are 20 μC cm −2 and 40 kV cm −1 , respectively, at 1 kHz. The dielectric constant and the loss tangent are about 600 and 0.02, respectively, at room temperature and 1 kHz.

(Pb, La)TiO3 (lead lanthanate titanate, PLT) ferroelectric thin films with a perovskite structure, whose composition agrees with stoichiometry and whose distribution is homogeneous, have been prepared on various substrates by sol—gel processing. Epitaxial PLT thin films have been prepared on Pt film substrates. They are (111) PLT|(111) Pt. The PLT thin films have good dielectric, ferroelectric, pyroelectric and optical properties. The dielectric constant and pyroelectric coefficient of PL15 films on a Pt film are 210 and 5.25 × 10−8 C cm−2 K−1, respectively, at room temperature. The remanent polarization Pr and the coercive field Ec of PL14 films on an Si wafer are 16.5 μC cm−2 and 60 kV cm−1, respectively. The optical transmittance of PL28 films deposited on quartz substrates is about 80% in the wavelength range 500–1000 nm.

The influence of heat treatment and substrate materials on PLT thin films by sol-gel processing has been researched. Epitaxial growth PLT thin films with perovskite-type structure on sapphire, SrTiO3 and MgO single crystal substrates have been prepared. The epitaxial relations are (100)PLT28/(100)SrTiO3, (111)PLT28//(0001)sapphire and (100)PLT14//(100)MgO. The PLT polycrystal thin films with perovskite-type structure on Si single crystal and quartz glass substrates have been prepared. The remanent polarization Pr and the coercive field Ec of PLT15 ceramic thin films are 7.7 μc/cm2 and 34 kv/cm at 4 KHz respectively. The optical transmittance of PLT28 ceramic thin films within the wavelength range of λ = 500–1000 nm is approximately 80%.