Unique nanostructures in NiCo alloy nanowires

NiCo alloy nanowires have been fabricated by electrodeposition using an anodized aluminum oxide (AAO) template. Single-crystalline and polycrystalline alloy nanowires have been obtained, and their microstructure was strongly dependent on the deposition conditions (current density and composition). In addition, unique nanostructures have been observed in NiCo alloy nanowires. Bamboo or layer structures were found for 15 and 25 at.% Co, respectively. The investigation of the mechanisms shows that these particular structures are related to the different diffusion rates of Ni and Co on the surface of the AAO template. The work demonstrates that as well as single-crystalline and polycrystalline nanowires, other unique nanostructures (layered and bamboo in this work) can be achieved through careful control of the preparation conditions. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.