Single-crystal growth of metallic nanowires with preferred orientation

Single-crystalline metallic nanowires, Ni, Ag, and Zn, were successfully fabricated using an anodic aluminium oxide (AAO) template by electro-deposition. The single-crystalline Ni and Ag nanowires showed face-centred cubic (fcc) structure with a preferred orientation along the [220] direction. Zn nanowires with hexagonal close-packed (hcp) structure also had preferred orientation along [220]. The structure of metallic nanowires depended on the deposition conditions and can be controlled by the conditions. Thermodynamics and electrochemistry were employed to analyse the growth mechanism. The competition among the nuclei and subsequent coalescence contributed to the formation of columnar structure within the nanopores of AAO, and H-adsorption led to the preferred orientation and single crystallinity.