Revealing the role of Co element on local structure and magnetism in Fe-Si-B-C amorphous alloys through calculations and experiments

Abstract

In order to understand the role of Co element on glass-forming ability(GFA) and magnetization of Fe-Si-B-C amorphous alloys, we analyse atomic structures, electronic structure and magnetic moments by ab initio molecular dynamics simulations.The GFA and magnetization of (Fe0.8Co0.2)83.6Si1B15C0.4 amorphous alloy are best in our experiment and simulation. According to calculations of the local structures, electronic structures, and magnetic moments,Fe-centered or Co-centered deformed body-centered cubic units and B-centered prism units predominate in the local structures of Fe-Co-Si-B-C amorphous alloys. In particular, the ratio of Co to Fe of 1:4 in (Fe0.8Co0.2)83.6Si1B15C0.4 amorphous alloy is the critical factor for enhancing GFA and magnetization, which improves the degree of atomic chaos, the stability of the local atomic structures and enhances magnetic moments. However, the excessive addition of Co leads glass-forming ability and magnetization to reduce.This work offers insight into the relationship between local atomic structures and Fe-Co-based amorphous alloy magnetization and offers suggestions for the development of high-performing soft-magnetic amorphous alloys.