Influence of anodizing conditions on the ordered pore formation in anodic alumina

Nanosize pore arrays have been prepared by the self-organization process of aluminium anodic oxidation. The symmetry of the pore configuration has been analysed by using fast Fourier transformation. For different anodization temperatures, it has been found that lower temperatures yielded higher symmetry. The linear relation of Ln sigma (a) versus T reveals that the anodization process is thermally activated with the apparent activation energy, E-c, of 0.52 eV. It was also found that the temperature has less influence on the ordered pore domain size than acid concentration. The largest domain size was observed for samples anodized under the conditions of 0 degreesC, 40 V, 0.6 M oxalic acid. The surface morphology of the acid solution/alumina and alumina/metal interface indicates that steady growth of alumina film at lower temperatures ceases the uneven local expansion of the alumina and contributes to the high asymmetry of pore arrays.