Structure and dielectric nonlinear characteristics of BaTiO3 thin films prepared by low temperature process

Ferroelectric BaTiO3 thin films were prepared by sol-gel-ethanol thermal technique (SGET) and sol-gel-hydrothermal technique (SGHT), respectively, at 200 degrees C. The microstructure characteristics proved that the prepared BaTiO3 thin films were both in the perovskite phase and had polycrystalline structure. The frequency dependences of nonlinear dielectric properties of the films were studied. The two films exhibited a high and very stable insulating characteristic against biasing. The films prepared by SHET tend to have a higher dielectric constant, loss, leakage current density and polarization than that of the films prepared by SGHT. The nonlinear variation of dielectric properties under external de bias field was tentatively explained. (C) 2008 Published by Elsevier B.V.