Fabrication of K₂Ta₂O₆ films by hydrothermal method and their optical property

Ta is one of stable and noble metals, and hard to be prepared complex oxides at low temperature. In this study K₂Ta₂O₆ thin films were fabricated on the Ta sputtered glass substrates by the hydrothermal method under relatively low temperature condition (393K, 12-72h). The transparency of deposited film increased after hydrothermal treatment due to the generation of K₂Ta₂O₆ from Ta metal. Fabricated K₂Ta₂O₆ films showed the pyrochlore type structure by XRD investigation. Optical properties of the films were investigated by the decomposition reaction of methylene-blue under the ultraviolet ray irradiation. About a 100 nm thick film of pyrochlore type K₂Ta₂O₆ was fabricated when the sputtering time was 300 s, and it indicated photo-catalyst property.