High-rate epitaxy of anatase films by atmospheric chemical vapor deposition

Crystalline orientation often provides particularly the anisotropy of chemi cal and physical properties. Since the epitaxial films are composed of high ly oriented crystals, it is expected that chemical and physical advantages are predominantly in one specific direction. In this study, high-rate epita xy of anatase films was attempted using a chemical-vapor-deposition techniq ue. Four types of epitaxial anatase films were obtained, i.e., (112), (110) , (100) and (001) oriented normal to the substrate surface. These films red uced methylene blue under ultraviolet irradiation. The reduction rate of me thylene blue was largely affected in the direction of crystalline orientati on.