FERROMAGNETIC-RESONANCE STUDIES OF EXCHANGE-COUPLED FE/NI MULTILAYERS

Multilayers of Fe/Ni have been deposited onto water-cooled glass substrates by a dc triode under computer-controlled conditions. The layer thickness was in the range 20 to 200 angstrom and the total thickness about 600 angstrom. FMR was observed at 9.8 GHz. The perpendicular spectra consisted of more than one mode. We have calculated the field positions of the modes and compared them with the experimental data and found that the latter were smaller by about 10%. In order to obtain a good agreement it is necessary to suppose the presence of an alloy layer about 20 angstrom thick at each interface with an average magnetization on the order of 13 kG.