チタンのアノード酸化皮膜の構造解析
1998 年 19 巻 12 号 p. 799-804
詳細
1998 年 19 巻 12 号 p. 799-804
Recent studies of the anodic oxide films on titanium are reviewed. In-situ electrochemical techniques including AC impedance, optical reflection like ellipsometry, photoelectrochemistry, and Raman spectroscopy have been used. The results are summarized as follows: (1) The TiO2 film is amorphous at potentials lower than 5 V but changes to anatase type at potentials higher than 5 V. (2) Thickness of the film is linearly proportional to the anodic potential in the poten-tials range lower than 7 V. However, the ratio of thickness to potential becomes larger if the potential is higher than 7 V probably due to formation of an ionic leakage path accompanied by crystallization of the film. (3) The film behaves as an n-type semiconductive electrode with a high concentration donor density and a bandgap of 3.2 eV.
