Induced magnetic anisotropy and stress-impedance effect in nanocrystalline Fe73.5Cu1Nb3Si13.5B9 ribbons

The influence of direction and strength of induced magnetic anisotropy on stress-impedance (SI) effect was experimentally and theoretically studied in this paper. Experimentally, it was found that the magnetic anisotropy of the stress joule heated Fe73.5Cu1Nb3Si13.5B9 nanocrystalline ribbons were determined by direction and strength of the induced anisotropy. Theoretical calculations of the direction and strength of the induced magnetic anisotropy suggest that transverse anisotropy and small anisotropic field result in an increase of the SI effect. To decrease the anisotropic field and increase the transverse anisotropy simultaneously, a complex annealing process was applied to Fe73.5Cu1Nb3Si13.5B9 ribbons, and it was found that the SI effect was drastically improved. A maximum change of 286% in the SI ratio of the complex annealed nanocrystalline Fe73.5Cu1Nb3Si13.5B9 ribbon was observed around 10 MHz frequencies.