A new self-ordering regime for fast production of long-range ordered porous anodic aluminum oxide films

Porous anodic aluminum oxide (AAO) films with large interpore distance (Dint, 307–415 nm) have been fabricated by using a new self-ordering regime in oxalic acid based electrolyte systems. The new regime corresponds to the stage with a stable voltage during constant-current anodization process, accompanied by high anodization voltage (Ua, 135–183 V) and current density (Ja, 300–500 A m–2) which facilitate the high speed growth of long-range ordered porous AAO films. In addition, the formation mechanism of the self-ordering regime, together with the influence of anodization conditions on the microstructural parameters of AAO films have been investigated in detail. Experimental results showed that the value of the stable Ua during constant-current anodization can be adjusted by varying the anodization conditions. Accordingly, the self-ordering window of the as-prepared porous AAO films can be modulated, widening the regulating range of Dint to a large extent.