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  • Electrodeposition of cobalt...
    Panzeri, Gabriele; Accogli, Alessandra; Gibertini, Eugenio; Varotto, Sara; Rinaldi, Christian; Nobili, Luca; Magagnin, Luca

    Electrochemistry communications, 06/2019, Letnik: 103
    Journal Article

    Ethylene glycol-based solutions containing metal precursor chloride salts were investigated for the electrodeposition of cobalt thin films and nanowires. The electrochemical behavior of 0.5 M Co(II) chloride solution at 70 °C was studied by means of cyclic voltammetry (CV) on a Pt substrate. The reduction process was shown to be irreversible, with high faradaic efficiencies (85–90 %). A diffusion coefficient (D0) of 2.29 × 10−6 cm2 s−1 for the Co species was estimated from the electrochemical behavior at different scan rates (from 25 to 125 mV s−1). The electrodeposition process was also studied on a copper substrate at different cathodic potentials (from −0.75 V vs Pt to −0.95 V vs Pt). Field-emission scanning electron microscopy (FE-SEM) and electron dispersive spectroscopy (EDS) revealed high-purity, compact films. Template-assisted electrodeposition resulted in ~16–18 μm long cobalt nanowires with an aspect ratio L/D > 100. X-ray diffraction (XRD) analysis of Co thin films showed a preferential orientation along the HCP 100 direction, which was even more marked for the nanowires. Vibrating sample magnetometry (VSM) highlighted that the fact that Co thin films were magnetized in-plane, while in nanowires a competition between shape and magnetocrystalline anisotropy led to similar magnetic behavior for the in-plane and out-of-plane directions. •Ethylene glycol is an effective solvent for the electrodeposition of cobalt.•Diffusion coefficient of cobalt ions is measured using the Randles-Sevcik equation.•Diffusivity of cobalt ions is higher than that in other organic solvents.•The magnetization of cobalt thin films preferentially lies in the film plane.•Cobalt nanowires show no magnetic anisotropy.