Fast Fourier transform based arrangement analysis of poorly organized alumina nanopores formed via self-organized anodization in chromic acid

Poorly arranged nanopores focus attention of the researchers due to the many fundamental aspects. Thus, quantitative arrangement analysis of non-ideally arranged pores is demanded. In the paper, radial average fast Fourier transform based arrangement analysis of the nanopores has been reported. This arrangement analysis tool has been applied in the quantification of arrangement of anodic alumina formed in 0.3 M chromic acid at voltage ranging from 20 to 50 V and temperature ranging from 20 to 50 °C. Presented approach, in contrary to typically applied methods, is based on the radial average of the fast Fourier transform (FFT). Averaged regularity ratio, estimated with the use of the reported tool, gives more repeatable results with smaller spread. Thus, reliable dependencies between operating conditions and the averaged regularity ratio can be also obtained for poorly arranged pores. It was found that the greater the voltage and temperature, the better nanopores arrangement.