Preparation of BaTiO₃ Thin Film by Hydrothermal Electrochemical Method

Abstract

BaTiO 3 thin films have been prepared in situ on Ti metal substrates by a hydrothermal electrochemical technique, where a direct current has been passed between the anode, Ti plate, and the cathode, Pt plate, in high-temperature, high-pressure Ba 2+ solutions. Dense thin films, 0.1∼0.3 µm thick, which consist of cubic BaTiO 3 polycrystals without apparent pores or defects have been obtained under the following conditions: in 0.25∼0.5 N-Ba(OH) 2 solutions above 100°C under saturated vapor pressures with the current density of 10∼100 mA/cm 2 after 30∼80 min. These films are paraelectric with the dielectric constant of ≈300.