Near-Zero Magnetostrictive Nanocrystalline Fe–Si–B–Cu–Nb Alloys Obtained After a High Heating Rate Annealing

A nanocrystalline Fe73.5Si15.5B7.0Cu1.0Nb3.0 alloy has zero-magnetostriction, $\lambda _{s}$ , a high saturation magnetic flux density, $B_{s}$ , of 1.23 T and a low coercivity, $H_{c}$ , of about 1.5 A/m. This article has been studied with a high heating rate annealing, leading to the finding that Cu-addition does not play an important role in good soft magnetic properties in nanocrystalline ribbons. Near-zero $\lambda _{s}$ is realized at a Si/Fe ratio of 0.21 which is the same as that of 0.21 for an existing zero-magnetostrictive nanocrystalline Fe73.5Si15.5B7.0Cu1.0Nb3.0 ribbon. A nanocrystalline Fe76.5Si16.0B6.0Nb1.5 ribbon annealed at 640 °C shows near-zero $\lambda _{s}$ of about $2.3 \times 10^{-6}$ and low $H_{c}$ of 1.1 A/m with a higher magnetic flux density at 8000 A/m, $B_{8000}$ , of 1.37 T which is higher than that of 1.23 T for the existing nanocrystalline ribbon.