The complementary effects of Fe and metalloids on the saturation magnetization of Fe-based amorphous alloys

Developing Fe-based amorphous alloys with high saturation flux density (Bs) have been challenging topics for a long time. Metalloid elements like B, Si, C, and P are key elements for Fe-based amorphous alloys, but the addition of multiple metalloids would significantly complicate the effects of each metalloid on saturation flux density. Herein, Fe83-85(B, C, Si)14–16P1 amorphous alloys with high Bs of 1.61–1.71 T and low coercivity (Hc) of 2.2–8.7 A/m were successfully developed. Fe and metalloids were found to have strong interrelated effects on the total magnetic moment and the strength of magnetic exchange interaction, which largely determine the Bs of Fe-based amorphous alloys. It was revealed that for Fe-rich amorphous alloys, the effects of metalloids on Bs are much more significant than that of Fe, and the effects are largely dependent on Fe content. The complementary effects of metalloids on Bs and the Fe-sensitive behavior of these effects, as well as the underlying mechanisms, have been revealed. These results pave a new way to understand the composition-property relationship, and would help design and develop high-performance Fe-based soft magnetic amorphous alloys.