A NEW PREPARATION METHOD OF BARIUM-TITANATE PEROVSKITE FILM USING ELECTROCHEMICAL REDUCTION

BaTiO3 perovskite film was prepared by electrochemical reduction in the solution containing both Ba2+ and Ti4+ ions. Heat-treatment at temperatures higher than about 700-degrees-C was necessary for crystallization, because the as-deposited oxide films were amorphous. The deposition occurred on stainless steel, Fe, Ni and Ti electrodes, but not on Pt and Al electrodes during the electrolysis. The composition of the deposited oxide film was strongly dependent on the applied potential and current density during the electrolysis. It wars judged from the measured voltammogram that the incorporation of Ba2+ ion into the deposited oxide during the electrolysis depends on electrochemical reduction in which H2O is consumed to produce OH- ion. Consequently, Ba2+ ion existed as a nitrate and a hydroxide or an oxide in the hydrated TiO2 owing to this electrochemical reduction. The mechanisms of the deposition of the BaTiO3 precursor and the crystallization of perovskite by heat-treatment are discussed.