| Nanometer pore arrays alumina films were prepared by anodizing of highly pure aluminum foils in sulfuric and oxalic acid solution. The porous alumina layers were detached from the Al substrate by using step-down voltage or solution method. The morphologies and structures obtained the anodized aluminum films were characterized by scanning electron microscopy (SEM). transmission electron microscopy (TEM) and atom force microscopy (AFM). The results show that the aluminum foils anodized under appropriate conditions have been evidently divided into three layers in which barrier-layer alumina films with arc bottom is between un-anodized aluminum and porous-layer alumina. The barrier-layer alumina films and porous-layer alumina make up of nanometer alumina membrane. The diameter of holes in porous-layer alumina is about from 50nm to lOOnm, and the distance between holes is about from 100 nm to 150nm. The cells and pores of porous anodized aluminum films are arranged in hexagons arrays; and the cells sizes and diameters of the pores that are on the scale of nanometer have narrow distribution. The cells in barrier anodized aluminum films are arranged in hexagonal arrays at aluminum/alumina interface. Furthermore, the effect of anodizing voltage on cell sizes, pore diameter, pore density and cell density are studied. Results indicate that in the given range cells sizes and pores diameters in porous anodized aluminum films increase with the increase of anodizing voltage, while pores densities and cells densities decrease with the of increase anodizing voltage. Through the IR transparent spectra, we found anion of anodizing electrolytes , also participate the formation of porous membrane during the anodizing procedure. The XRD spectra of the membrane showed the formation of amorphous alumina. The property of optics and electricity for alumina films was researched.
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