SPIN DYNAMICS AND MAGNETIC-ANISOTROPY DISPERSION IN SOFT FERROMAGNETIC THIN-FILMS

An analytic calculation of the permeability frequency spectra using th e LANDAU-LIFSHITZ theory is compared with experimental results obtaine d on ferromagnetic thin films with an in-plane uniaxial magnetic aniso tropy. The disagrement between theory and experiment is attributed to magnetic anisotropy. dispersion in the film. This dispersion is studie d and seems to be due to magnetic ripples. Measurement of the ripple e ffect is done through the measurement of the transverse biased suscept ibility. A quantitative evaluation of the anisotropy dispersion is sug gested in order to improve our model.