Fabrication And Properties Of One-dimensional Nano Arrays

In recent years, more and more attention has been paid on the template-assisted synthesis of nano-materials because of its unique properties and potential applications. AAO(anodic aluminum oxidation) membrane has a highly-oriented porous structure, which makes it become an ideal template for preparing nanowires. To date, many metal and semiconductor nanowire arrays have successfully been prepared by applying AAO as a template.In this paper, AAO membrane has been prepared by aluminum anodization in an oxalic acid electrolyte under constant potential and temperature. Besides, the configuration and mechanism of AAO has been investigated by SEM, AFM, XRD. The results show that the AAO membrane is composed of two layer, i.e. porous layer and barrier layer. The porous layer contains high-density holes, which are parallel to each other, however the barrier layer is compaction. Porous AAO membrane is in amorphous state. The growth of AAO is affected by many factors, especially electric field.Ni, Co and their alloy nanowires have been fabricated by alternating current electrodeposition using two-step AAO template. TEM, XRD and VSM have been employed to investigate it. The results show that the nanowires exhibit highly aspect ratio, which display obvious preferred orientation and magnetic anisotropy. They are promising for a candidate of magnetic recording media. By comparing the pattern's macro magnetic performance before/after annealing, the magnetization reversal of magnetic nanowires has been studied.Besides, the CdS nanowires have been fabricated in AAO template by alternating current electrodeposition. The morphology and optical performance have also been investigated. The results indicate that the CdS nanowires crystallize in an hcp structure, and have a preferred orientation. Photoluminescences (PL) of CdS nanowire arrays characterized by spectrophotometer shows CdS nanowries embedded in porous alumina template increase the light-emitting intensity.