Abstract
The self-organized anodic aluminum oxide mask provides low cost, high throughput, large scale and fundamentally simple processes to creat periodic nanostructures. Camparing with using the tranditional electrolytes, electropolished Al foils were anodized by two-step anodization in sulfuric/oxalic acid mixture with different proportion as electrolyte at different applied voltages to induce the ordered structure in a wilder range of interpore distance. The morphologies of these samples were examined by scanning electron microscope (SEM). In the thesis, different interpore distances (82, 78, 66, 63, and 58 nm) of ordered porous alumina were carried out by anodization in different proportional sulfuric/oxalic acid mixture solution as electrolyte at specific voltages (33, 29, 26, 24, and 21V). Other acids as electrolyte were also used in the experiment. On the other hand, the titanium oxide nanodots with 96nm interval and silicon oxide nanodots with 65nm interval were prepared successively from Al/Ti films on silicon substrate and Al film on silicon substrate by locally electrochemical anodization. Ordered Pt and Ni nanodots arrays with spacing distance of 100nm were fabricated using ultra-thin (~100nm) porous alumina as a mask by sputter deposition and evaporation deposition, respectively. After annealing Pt particles under 800°C, the shape of Pt nanostructure changes from disc to spherical-dot shape. Moreover, large ranged of highly ordered Ni nanowires with shape anisotropic magnetic properties were synthesized by electrodeposition by using high-aspect-ratio porous alumina as template. The length of appearance nanowire tips can be easily adjusted by wet etching in NaOH solution for suitable time. This approach offers considerable versatility in the choice of materials.