Prediction of the frequency dependence of the magnetic permeability at low fields in magnetic amorphous ribbons

We consider a theoretical ribbon which, on average, represents the behavior of the sample. We calculate the physical response of the sample when an ac magnetic field below a critical field is applied. This model has been used previously to predict successfully properties of amorphous ribbons for static fields. Here, we propose an extension of this model to predict the frequency spectra for the initial magnetic permeability. We found a very good agreement with experimental results for a VITROVAC 6025 ribbon. We also obtained the value of the dissipative constant and the value of the effective mass of the domain wall.