Composition dependence of amorphous forming, crystallization behavior, magnetic and electronic properties of silicon-rich FeSiBCuNb alloys

Abstract

Fe-Si-B-Cu-Nb nanocrystalline alloys have been commercially applied at higher frequencies. However, few research works are focused on improving high-frequency magnetic properties for these alloys. In this paper, we reported crystallization behavior, soft magnetic properties and permeability spectra for silicon-rich Fe72.5Si16B7 Cu1Nb3.5-xMx (where × = 1.5 and M = Nb, P, Mo, V) nanocrystalline alloys prepared by crystallization from amorphous precursors. Through the copper roller melting spinning technique, we can attain complete amorphous alloy ribbons when M is 1.5 at.% Nb, P or Mo. After annealing at appropriate temperatures, by comparison with the alloy of M = 1.5 at.% Nb, the alloy with addition of 1.5 at.% P shows a lower coercivity (Hc = 0.8 ~ 1.5 A/m), and a higher effective permeability (µe) at 1 kHz–20 kHz (µe = 116,600 at 1 kHz) while the µe gets much lower at 30 kHz–200 kHz; the alloy with addition of 1.5 at.% Mo exhibits a larger Hc (Hc = 2.9 ~ 3.4 A/m), and a lower µe at 1 kHz − 20 kHz but then the µe becomes higher at 30 kHz–200 kHz (µe = 31,000 at 100 kHz).