Magnetization reversal in patterned ferromagnetic and exchange-biased nanostructures studied by neutron reflectivity (invited)

We have measured the off-specular polarized neutron reflectivity of periodic arrays of micron-sized rectangular polycrystalline ferromagnetic Co bars and exchange-biased Co/CoO bars, which were prepared by a combination of electron-beam lithography and evaporation techniques. The intensity of the first-order off-specular neutron satellite reflection was monitored as function of the magnetic field parallel to the long edge of the bars, allowing analysis of the magnetization reversal process using the four spin-polarized scattering cross sections. The neutron data are compared with calculations based on a micromagnetic simulation. The influence of shape anisotropy on the reversal mechanism is demonstrated.