Glass-Forming Ability and Magnetic Properties of ()}}}}}}}~(}=, 17) Amorphous Alloys

The glass-forming ability (GFA) and the magnetic properties of the (Fe 0.80 Co 0.20 ) 96-x B x Si 1 Nb 3-y Y y (x = 15, 17) amorphous alloys have been studied. It was confirmed that GFA is enhanced by replacing Nb with Y. Yttrium gives a complex effect on the magnetization. When Y content is increased, the saturation mass magnetization (σ s ) decreases first. However, the σ s then increases and exhibits a maximum ~2 at% Y. The value of σ s of the alloy with x = 17 and y = 2 in an as-quenched state is 211 × 10 -6 Wb m/kg, which is slightly larger than that of the Y-free alloy with the same B content. The values of the coercivity of these alloys are less than 10 A/m in an as-quenched state. The coercivity shows a tendency to decrease with increasing Y content, which means the increase of GFA. These results indicate that the partial replacement of Nb by Y in the Fe-Co-B-Si-Nb alloys is useful to the simultaneous achievement of high GFA, high σ s , and good soft magnetic properties.