Ferromagnetic Resonance for Electromagnetic Waves Passing through Metal Superlattices

Ferromagnetic-resonance-induced variations in the transmittance of Fe films and Fe/Cr superlattices are studied in a microwave frequency interval of 26–38 GHz. The shape of the resonance line is described using a model in which the asymmetry is provided by a Lorentzian dispersion curve added to the absorption curve. It is shown that the line shape is well described using the model for superlattices with continuous Fe and Cr layers and Fe films. However, only qualitative agreement is obtained for superlattices with thin Fe and Cr layers. The experimental field dependence of the transmission coefficient substantially differs from the model results in the presence of the fields that are less than the field of ferromagnetic resonance for superlattices with giant magnetoresistance.