The permeability dispersion in ferrites at different levels of direct current magnetic biasing

The magnetic spectra of polycrystalline ferrites of different compositions and microstructure measured in a weak alternating field combined with a dc biasing field are analysed. A model to explain the influence of biasing field on the domain walls of different sizes is proposed. This model explains the change of the low-frequency permeability value, the modification of the character of the magnetic spectrum, and the shift of the dispersion frequency region occuring under the influence of the biasing.