TEM Analysis of Multilayered Co/Cu Nanowire Synthesized by DC Electrodeposition

Abstract

As-received multilayered Co/Cu nanowire arrays were examined by TEM, which were synthesized by pulsed DC electrodeposition using anodized aluminum oxide (AAO) templates. The multilayered Co/Cu nanowire exhibited magnetism in the perpendicular direction to the long wire axis. These nanowire can be applied to sensor array, magnetic bead(biocompatible), MRI contrast enhancing agent, ferro-fluid. Although the characterization of the multilayered Co/Cu nanowire using XRD and VSM and microstructural analysis using TEM on the bare nanowires extracted from AAO templates have been reported, interface analysis between Co and Cu phase or HREM analysis has not been reported in detail. We have prepared TEM specimen with large thin area which was appropriate for the interface analysis between Co and Cu layer without removing AAO templates using tripod polishing method. Tripod polishing proved very efficient to secure the large observable area during TEM session since the polishing angle can be precisely controlled, regardless of the mechanical strength differences in constituents. Thus we could observe not only the interface between Co and Cu layer but also the interface between the metallic layers and AAO templates. Microstructure, composition, and the concentration variation of each Co and Cu layer and the interfaces were analyzed with TEM and STEM.