Preparation and Characterization of BaTiO_3 Powders by Sol-gel and BaTiO_3 Ferroelectric Films by Electrophoretic Deposition Technique

摘要

The clear and transparent sols of BaTi acetate were prepared from tetrabutyltitanate, barium acetate aqueous solution, ethanol and acetic acid. The BaTi acetate sols were transferred into gels by sol-gel process, and the gels were dried and calcined to nanostructured BaTiO_3 powders. Pure barium titanate powders added in mixtures of acetone and iodine and water or acetylacetone (Acac) and ethanol (EtOH) as suspension systems, the aim of this study was to use the electrophoretic deposition technique (EPD) to fabrication the BaTiO_3 ferroelectric films with high dielectric constant. During sol-gel transition process, it is found that the initial PH value of sol affected not only the sol-gel transition, but also the particles size of the final calcined BaTiO_3 powders. The effects of the EPD process parameters such as the suspension, powder concentration, electrical field strength on the specific EPD deposited weight were investigated. The films sintered at 1050℃ for 2h were crystallized into the tetragonal phase at room temperature, which were sufficiently dense and had uniform microstructure and excellent dielectric properties.