The effects of the electrolytic bath acidity, or pH, on the magnetic properties in arrays of electrodeposited Co nanowires and their correlation with the crystalline properties have been studied using ferromagnetic resonance. The results show that, depending on the value of the pH of the electrolyte, appreciable changes in the effective anisotropy can be induced. These changes are attributed to modifications in the microstructure of the Co nanowires. In particular, quantification of the effective anisotropy field shows that the microstructure of the deposited Co wires can be set to contain a dominant fraction of the Co-hcp phase with the c-axis oriented perpendicular to the wires, for pH values of 3.8–4.0, or parallel to the wires, for pH values ⩾6.0. This results in a competitive or additive magnetocrystalline contribution to the total anisotropy field. Furthermore, at a pH value of 2.0, no contribution from the magnetocrystalline anisotropy is present, indicating a lack of texture in the Co microstructure. As a result, the effective anisotropy can be controlled over a field range of 5 kOe.

In this letter we present a convenient way of controlling the direction of the uniaxial magnetocrystalline anisotropy in arrays of electrodeposited hcp Co nanowires. Combining electron microscopy and ferromagnetic resonance measurements, it is shown that using an appropriate pH of the electrolytic solution, the hcp c axis can be oriented parallel or perpendicular to the wires axes simply by changing the deposition current density or deposition rate. This reorientation of the c axis leads to a drastic change in overall magnetic anisotropy as the crystal anisotropy either competes for perpendicular oriented c axis or adds to the shape anisotropy for parallel oriented c axis.

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We present an experimental investigation of a class of microwave photonic band-gap (PBG) materials, in which the magnetic permeability μ varies periodically within the material. This material is fabricated using a periodic arrangement of arrays of magnetic nanowires. As for dielectric or metallic PBG, the band-gap behavior varies with the geometrical parameters fixing the spatial periodicity of the magnetic structure. The magnetic photonic band gap is induced by the presence of a ferromagnetic resonance effect in the vicinity of the band gap.

This article is focused on the use of electrodeposition and of various nanoporous templates for the fabrication of metallic nanowires made from single metals (Ni, Co, Pb, Sn), alloys (NiFe, CoFe, CoPt), and multilayers (Co/Cu, NiFe/Cu). An overview is given of our recent studies performed on both magnetic and superconducting nanowires. Using different approaches entailing measurements on both single wires and arrays, numerous interesting physical properties have been identified in relation to the nanoscopic dimensions of these materials. Finally, various novel applications of the nanowires are also discussed.