Dielectric Properties of Multilayered Ferroelectric Thin Films Fabricated by Sol-Gel Method

Multilayered thin films of ferroelectric perovskites were fabricated by the sol-gel method. The investigated films were PbTiO₃, PbZrO₃, BaTiO₃ and SrTiO₃, and their multilayered films. The films were prepared by dipping and heating in air at 600–700° C. The microstructures and crystalline phases of the single component and their multilayered films were examined. The multilayered film of PbTiO₃ and PbZrO₃ has a very clear interface between the components, though that between PbTiO₃ and SrTiO₃ was not clear due to the diffusion of the lead component from the PbTiO₃ layer into the SrTiO₃ layer and the formation of a solid solution. The dielectric constant of the multilayered films and its dependence on temperature could not be explained by the series connection of those of the component films.