Surface modification of Ni and Co metal nanowires through MeV high energy ion irradiation

Nickel (Ni) and cobalt (Co) metal nanowires were fabricated by using an electrochemical deposition method based on an anodic alumina oxide (Al2O3) nanoporous template. The electrolyte consisted of NiSO4 · 6H2O and H3BO3 in distilled water for the fabrication of Ni nanowires, and of CoSO4 · 7H2O with H3BO3 in distilled water for the fabrication of the Co ones. From SEM and TEM images, the diameter and length of both the Ni and Co nanowires were measured to be ∼ 200 nm and 5–10 μm, respectively. We observed the oxidation layers in nanometer scale on the surface of the Ni and Co nanowires through HR–TEM images. The 3 MeV Cl2+ ions were irradiated onto the Ni and Co nanowires with a dose of 1 × 1015 ions/cm2. The surface morphologies of the pristine and the 3 MeV Cl2+ ion-irradiated Ni and Co nanowires were compared by means of SEM, AFM, and HR–TEM experiments. The atomic concentrations of the pristine and the 3 MeV Cl2+ ion-irradiated Ni and Co nanowires were investigated through XPS experiments. From the results of the HR–TEM and XPS experiments, we observed that the oxidation layers on the surface of the Ni and Co nanowires were reduced through 3 MeV Cl2+ ion irradiation.