Quantitative arrangement analysis of anodic alumina formed by short anodizations in oxalic acid

Fast Fourier transform (FFT) based quantitative arrangement analysis was performed for the model periodic structures. Number of pores, surface area and porosity of the structures influence the FFT-based regularity ratio. Elimination of these effects allowed one to obtain convenient tool for quantitative arrangement analysis of anodic aluminum oxide (AAO). Researched AAO nanostructures were formed in 0.3 M oxalic acid via two-step self-organized 15-minute long processes. Temperature of electrolyte was ranging from 35 to 50 °C and anodizing voltage was ranging from 20.0 to 60.0 V. The greatest values of regularity ratio were obtained for anodic alumina fabricated at 40.0 and 50.0 V. Defect analysis, performed with Delanuay maps, has shown that the lowest values of defects percentage were for alumina obtained at 40.0 and 50.0 V. This finding is in agreement with FFT-based regularity ratio. The lowest values of circularity, describing nanopores shape, were obtained for anodic aluminum oxide fabricated at 60.0 V. Multi way analysis of variance of the regularity ratio, defects percentage and circularity has shown that both: anodizing voltage and electrolyteʹs temperature influence the nanopores arrangement.