アルミニウムアノード酸化皮膜の発色機構のESRによる研究
加熱による色の変化について
1976 年 27 巻 10 号 p. 521-525
詳細
1976 年 27 巻 10 号 p. 521-525
The origin of golden color of Al2O3 films formed in organic acid electrolytes has been investigated by using ESR, IR and pyrolytic gas-chromatography. In the course of the pyrolysis process in air or argon atmosphere, the film color changed and the deepness of the color was proportional to the spin concentration of the Al2O3 films, whereas the amount of the effluent CO2 gas during pyrolysis was not always proportional to the color. The location of spin free electron was determined by the ESR spectra of stable isotopes, 2H, 17O, and 13C introduced to the constituents of the anodizing electrolyte. Spin free electron was found to be situated near C atom rather than either H or O atom. From the ESR spectra of pyrolysis products of Al(OH)3 and organic acid mixture, it seems that the golden color is chiefly due to some intermediates formed by carbonizing process of the organic acids incorporated in the Al2O3 matrix, although the substances are not identified yet.
