Nb-Poor Fe-Nb-B nanocrystalline soft magnetic alloys with small amount of P and Cu prepared by melt-spinning in air

The effect of the addition of P and Cu to Fe85Nb6B9 alloy on an as-quenched structure and soft magnetic properties in a nanocrystallized state has been investigated. The Fe85Nb6B9 alloy melt-spun m air has an as-quenched structure of an amorphous phase and alpha-Fe grains with 20-45 nm in size. The coarse grains should still remain in the nanocrystallized structure, which deteriorates the soft magnetic properties. The simultaneous addition of 1 at.% P and 0.1 at.% Cu to the Fe85Nb6B9 alloy decreases the alpha-Fe grain size to nanoscale in an as-quenched state, and realizes a uniform crystallized structure with high saturation induction of 1.61 T as well as high permeability of 41,000. (C) 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.