Structure and soft magnetic properties of FINEMET type alloys: Fe73.5Si13.5Nb3 − x Mo x B9Cu1 (x = 1.5, 2)

Abstract

FINEMET type ribbons (Fe 73.5 Si 13.5 Nb 3−x Mo x B 9 Cu 1 , x = 1.5, 2 at.%) were produced by the planar flow casting technique and subsequently heat treated at 823 K to induce nanocrystallization and to optimize its soft magnetic properties. The coercivity, measured by conventional fluxmetric method, resulted in H C = 0.53 ± 0.10 and 0.41 ± 0.05 A/m for x = 1.5 and 2 respectively. A correlation between magnetic properties and the amorphous and nanocrystalline phases when Nb was partially substituted with Mo was studied by means of Mössbauer spectroscopy and X-ray diffraction.

Magnetostrictive behaviour of Fe73.5Si13.5B9Nb3−xMoxCu1 alloys

“…Previous results on the study of these alloys showed that the replacement of Nb for Mo increased both the crystalline fraction and the amount of Si in the nanograins when the heat treatment was kept at 813 K for 1 h [16]. Based on these two facts, we would have expected a decrease of the l S for these treated alloys with Mo addition, since l S sensitively depends on the crystal fraction and on l S,Cr (l S of the crystalline phase), which varies with Si content in the grains [11].…”

“…Based on these two facts, we would have expected a decrease of the l S for these treated alloys with Mo addition, since l S sensitively depends on the crystal fraction and on l S,Cr (l S of the crystalline phase), which varies with Si content in the grains [11]. However, l S also depends on l S,Am (l S of the amorphous phase) which in turn varies with the composition of the amorphous remaining matrix and its change with Nb/Mo rate has been reported [16]. Measured l S values showed no trend with the exchange of refractory elements neither for the asquenched ( $ 19 ppm) nor for the annealed samples ( $ 2 ppm).…”

“…X-ray diffraction, Mössbauer spectroscopy and coercivity were studied in Refs. [16,17]. The present paper discusses experimental results of spontaneous volume magnetostriction, magnetostriction, volume magnetostriction and forced volume magnetostriction obtained for Fe 73.5 Si 13.5 B 9 Nb 3À x Mo x Cu 1 alloys.…”

Study on soft magnetic properties of Finemet‐type nanocrystalline alloys with Mo substituting for Nb

“…In a number of studies, Nb was substituted by other elements such as V, Cr, Mo, etc. . In the literature , Silveyra et al studied Fe 73.5 Si 13.5 B 9 Nb 3− x Mo x Cu 1 ( x = 1.5, 2, at.%) alloys annealed at a fixed temperature and time by Mossbauer spectrum method.…”

“…. In the literature , Silveyra et al studied Fe 73.5 Si 13.5 B 9 Nb 3− x Mo x Cu 1 ( x = 1.5, 2, at.%) alloys annealed at a fixed temperature and time by Mossbauer spectrum method. The results indicated that H c was decreased due to the reduction on the effective anisotropy constant, and the crystalline fraction in Mo‐doped Finemet increased.…”