The Effect of Duration of First and Second Anodization Steps on the Ordering of Nanopores in Anodic Aluminum Oxide Templates Achieved by Three Step Anodic Oxidation Process

We report on the enhancement of naturally-occurred self ordering of nanopores in anodic aluminium oxide (AAO) membrane by performing three-step anodic oxidation process. Naturally-occurred self ordering of nanopores in anodic aluminium oxide (AAO) membrane has brought it into the applications of template for fabrication of nanoscale materials. Three-step anodic oxidation method was used to achieve self-ordering of nanopores. The effect of duration of first and second steps on the ordering of nanopores was investigated. The current-time curves recorded during anodization elucidate an almost same behavior for all three steps. Scanning electron micrographs (SEM) show hexagonally arranged 45 nm pores in a manner which contribute into the formation of highly ordered areas, called domains. Larger ones are clearly observed over the surface, for samples with longer first and second anodization steps.