Ferromagnetic resonance investigations of ion beam modified Fe- and FeNi-films

Ion beam induced modifications of the magnetic properties of thin ferromagnetic films were investigated with the sensitive ferromagnetic resonance. The effects of compositional changes were studied by high dose Ni-implantations into polycrystalline Fe/sub 20/Ni/sub 80/-alloy-films, which lead mainly to a reduction of the magnetization due to Ni-enrichment. On the other hand the influences of radiation damages and ion beam mixing were investigated by Fe-irradiations in epitaxial Ag/Fe/Ag-layers. The irradiations result in a decrease of the uniaxial-perpendicular- and of the magnetocrystalline-anisotropy constant, which is attributed to strain relaxation. At high fluences of 10/sup 16/ cm/sup -2/ we observed a change of the magnetocrystalline anisotropy from cubic towards a tetragonal symmetry.