Magnetic properties of Co-B nanostructures prepared via electroless deposition

We have investigated the magnetic properties of nanostructured Co-B alloys, prepared via electroless deposition. The deposition process results in the formation of a nanostructure consisting of nanotubes connected to thin films at both ends. Depending on the deposition time end-open or end-closed nanotubes can be formed. The overall nanostructure of Co-B deposit has a specific magnetization of 65.6 ± 8 JT^-1Kg^-1 (0.75 ± 0.09 μ_B per Co atom). We investigated the anisotropy and coercivity of the nanostructure by carrying out magnetic measurements with and without the top and base films. Magnetic anisotropy is observed in nanostructures with thin films, while nanotubes with the film removed do not display any significant anisotropy. Minimum coercivities of 550 ± 10 A/m and 4540 ± 40 A/m were recorded parallel and perpendicular to the nanotube axis with an associated film present. The coercivity values increased to 8750 ± 50 A/mand 7160 ± 50 A/m parallel and perpendicular to the nanotube axis, when the film was removed.