Abstract: Highly oriented barium titanate (BaTiO₃) thin films on Pt substrate were fabricated by combination of electrophoretic deposition with hydrothermal treatment. The structure and morphology of thin films were characterized by X-ray diffraction and field-emission scanning electron microscopy. It is found that the titania precursor film, Ba(OH)₂  oncentration and hydrothermal temperature play crucial roles in the film morphology and orientation. The BaTiO₃ thin films with highly (110) preferred orientation can be formed on  polycrystalline Pt substrate by appropriate adjustment of the reaction conditions. The orientation parameter f of highly oriented BaTiO₃ films was up to 1.00. The films exhibited a smooth and crack-free surface and remained in the layered structure. In situ topotactic transformation and dissolution-crystallization mechanisms were proposed to explain the morphology and orientation of BaTiO₃ films during hydrothermal treatment.

Key words: Barium titanate, Preferred orientation, Electrophoretic deposition, Hydrothermal treatment