The influence of the mesoscopic structure of Fe73.5Cu1 Nb3Si13.5B9 powder on its giant magneto-impedance effect

Based on the producing and the measuring impedance of Fe73.5Cu1 Nb3Si13.5B9 nanocrystalline powder, through abstraction, we propose a model (spherical mesoscopic structure model) exploring for the influence of the mesoscopic structure on the giant magneto-impedance (GMI) effect this kind of Fe-based nanocrystalline powder. Analysis shows that the GMI effect is closely related to the D-function, which is dependent on the following factors, such as μ (the effective magnetic permeability of the nanocrystalline grain), σ (its the electrical conductivity), R (its radius), ω (the driving field frequency), H0 (the driving field effective magnitude), Hex (the external DC magnetic field magnitude), and there exist mutual influences among μ, α, ω, R. With this model, we can succeed in exploring the influence of Hex on the resonance frequency, the resonance amplitude value, the sensitivity of the impedance curves of Fe73.5Cu1 Nb3Si13.5B9 nanocrystalline powder.