Effect of local magnetic anisotropy on the spin-wave resonance in amorphous thin films

On the spin‐wave‐resonance spectra corresponding to Co100−xZrx thin films, all the resonance fields, including the one corresponding to the uniform mode, follow a quadratic dispersion law with excellent precision. The intensities of the spin‐wave modes are very weak. The overall results are fairly well explained by a new model where it is shown that the characteristics of the spectra are determined by the random local anisotropy Kl. The value of the deduced Kl decreases with decreasing Ms as predicted by the single‐ion anisotropy theory.