Investigation of structural and magnetic properties of nanoscale Fe/Co bilayers

To understand the effects of deposition order and ion implantation on magnetic films, we have prepared Fe/Co and Co/Fe nanoscale bilayers by ion beam sputtering technique on Si(100) substrates. Implantation of 35 keV nitrogen ions in the presence of an in-plane magnetic field was done to modify the magnetic anisotropy at the nanoscale. The resulting microstructure and magnetic properties have been studied by X-ray diffraction and Magneto-Optical Kerr Effect. X-ray diffraction patterns of both the films give strong structural texture. The two films exhibit very different magnetic properties in terms of coercivity, anisotropy and domain structure. Two-fold uniaxial anisotropy has been observed in case of Sub./Co/Fe film while Sub./Fe/Co gives isotropic behaviour. Ion irradiation does not change the anisotropy in the film up to the ion fluence of 2 × 1016 ions/cm2. Reduction in the coercivity up to 2 × 1016 ions/cm2 has been observed in Sub./Fe/Co bilayers.