Ferromagnetic resonance in soft Cu/FeCo

We present the results of ferromagnetic resonance (FMR) measurements of soft Fe65Co35 thin films grown on a seed layer of Cu. FMR is investigated at different magnetic field orientations and over a broad range of frequencies from 3 to 94 GHz. The observation of spin wave resonances in the perpendicular orientation allows us to estimate the exchange stiffness.