A low-temperature and low-cost method to produce high-quality epitaxial anatase TiO₂ thin films

Epitaxial anatase TiO₂ thin films were successfully grown on lattice-matched SrTiO₃ (001) substrates by a novel hydrothermal method at very low temperatures (120–200 °C). This method is extremely simple and inexpensive in that the SrTiO₃ substrate itself provides the source material for the TiO₂ film. X-ray diffraction confirmed the high crystallinity and phase purity of the anatase films. The epitaxial relationship between the film and the substrate was determined as (001)[100]anatase // (001)[100]SrTiO₃. Atomic force microscopy revealed the average size of the anatase crystallites as approximately 50 to 200 nm.