Nanostructured soft magnetic material with low loss and low permeability

Nanostructured Fe–Cu–Nb–Si–B ribbons with relative permeability of a few hundred were prepared by using creep-induced anisotropy and their soft magnetic properties were evaluated. The observed domain pattern for an obtained ribbon suggests that magnetization process is due to the magnetization rotation mode. The variation of magnetization by its rotation results in frequency-independent behavior of the permeability up to 1 MHz with magnetic loss comparable to that of ferrite cores. A large saturation magnetization of the studied ribbons enables us to obtain the figure of merit for applications to the storage of magnetic energy being much larger than that of ferrite cores with air gaps. These results suggest that the Fe–Cu–Nb–Si–B ribbons with creep-induced anisotropy are suitable for a magnetic material for the storage of magnetic energy.