Reporting their results in the journal Nanotechnology, S K Arora and colleagues have fabricated planar NW arrays of Co on oxidized step-bunched vicinal Si templates using a shallow angle deposition technique named ATLAS (atomic terrace low angle shadowing). The method allows the team to tailor the width and inter-wire separation of the nanowires by selecting the appropriate combination of deposition angle, flux direction and template periodicity. This opens up a wide range of possibilities to investigate the magnetic interactions, magnetization dynamics and spin transport at the nanoscale.

In the study, the team from Trinity College Dublin in collaboration with researchers from the Catalan Institute of Nanotechnology show that the NW arrays with wire widths down to 25 nm are FM at 300 K. These NW arrays display an easier approach towards magnetic saturation for a magnetic field applied parallel to the wire length than across the structure.

The in-plane uniaxial anisotropy is dominated by the shape of the wires and is preserved at low temperatures (10 K). The group also reports on the magnetization reversal properties of the Co NW arrays, which depends on the thickness of NWs. This process is governed by the curling mode reversal for thick wires, whereas thinner wires exhibit a more complex behaviour related to thermal effects and size distribution of the crystal grains that constitute the NWs.

More information can be found in the journal Nanotechnology.