Uniaxial Magnetization and Electrocatalytic Performance for Hydrogen Evolution on Electrodeposited Ni Nanowire Array Electrodes with Ultra-High Aspect Ratio.

Ni nanowire array electrodes with an extremely large surface area were made through an electrochemical reduction process utilizing an anodized alumina template with a pore length of 320 µm, pore diameter of 100 nm, and pore aspect ratio of 3200. The electrodeposited Ni nanowire arrays were preferentially oriented in the (111) plane regardless of the deposition potential and exhibited uniaxial magnetic anisotropy with easy magnetization in the axial direction. With respect to the magnetic properties, the squareness and coercivity of the electrodeposited Ni nanowire arrays improved up to 0.

Determination of Activation Overpotential during the Nucleation of Hcp-Cobalt Nanowires Synthesized by Potentio-Static Electrochemical Reduction.

The crystal growth process and ferromagnetic properties of electrodeposited cobalt nanowires were investigated by controlling the bath temperature and cathodic overpotential. The cathodic overpotential during electrodeposition of cobalt nanowire arrays, Δ, was theoretically estimated by the difference between the cathode potential, , and the equilibrium potential, , calculated by the Nernst equation. On the other hand, the activation overpotential, Δ, was experimentally determined by the Arrhenius plot on the growth rate of cobalt nanowire arrays, , versus (vs.

Effect of Growth Rate on the Crystal Orientation and Magnetization Performance of Cobalt Nanocrystal Arrays Electrodeposited from Aqueous Solution.

The formation work of a two-dimensional hcp-Co (metallic cobalt crystal with hexagonal close packed structure) nucleus, , was calculated by Pangarov's theory. was estimated to be smaller than in a cathode potential range nobler than the transition potential, (ca. -0.