Variations of the permeability with annealing conditions for Fe-based nanocrystalline alloys

Considering the effective magnetic anisotropy of Fe-based nanocrystalline alloys contributed by the structure anisotropy and the induced anisotropy, an improved model of permeability was proposed within the framework of the random anisotropy theory. The dependence of permeability on the annealing time and temperature was analyzed, especially the peak value of permeability as a function of annealing time were explained by using this improved model. It is shown that the optimization annealing carried out at higher temperatures is more efficient and brings better soft magnetic property. The theoretical values were compared with the experimental data of a series of Fe-based nanocrystalline alloys. The results show that the theoretical analyzes are in excellent agreement with existing experiments.