Time and orientation dependence of ordering in anodized aluminum for self-organized magnetic arrays

Anodization experiments to create alumina pores were performed using pure Al and hard disk Al-Mg substrates. A single step anodization was employed for up to 40 h to determine the time dependence of pore ordering. The pores formed from the Al-Mg substrate were unordered, while ordered-pore domains as large as 3 mu m form in both the as-rolled and annealed pure Al samples. The effect of the aluminum grain crystallographic orientation was investigated via orientation-imaging microscopy for the pure Al surface with both order and disordered pores. It was found that neither heat treatment nor crystallographic orientation played a large role in the pore ordering. (C) 2000 American Institute of Physics. [S0021-8979(00)35308-7].