Preparation Of Metal-alumina Composite Film And Study Of The Optical Property

Porous aluminum oxide films were prepared by anodization of Al sheets. The factors that affect porosity were studied. The results show that the porosities of films prepared in sulfuric acid is bigger than that of films prepared in phosphoric acid and oxalic acid. Porosities increased with increasing temperature and decreasing voltage of oxidation process. Porous aluminum films with different porosities were prepared by changing the conditions. Made Cu,Ag,Ni,Au,Cu and Ag deposit in the microporous to prepare composite films. Their absorption spectrometries were studied. The results show that Cu-Al2O3,Ag-Al2O3,Au-Al2O3 have characteristical absorbability between 300~800nm; Ni-Al2O3 didn't show characteristical absorbability in visible light region. Spectrometry of Cu-Ag-Al2O3 was affected by Cu,Ag depositing order. Absorption value were decreasing when metal volume fraction reducing. Extinction coefficients and indexes of refraction were calculated by using Maxwell-Garnett theory. The results show that the optical constants decreased with the decrease of metal volume fraction. Theoretical calculations were in accord with the experimental results. Therefore, the Maxwell-Garnett theory can be a better simulation of optical properties of metal-alumina composite film in 300~800nm range.