Revealing the Impact of Ferromagnetic Elements on Fe-Based Amorphous Alloy Properties via ab initio Molecular Dynamics Simulations and Experiments

Abstract A high saturation magnetic flux density ( B s ) is essential for the development of Fe-based amorphous alloys for electromagnetic devices and motors. However, achieving a high B s often compromises the glass-forming ability (GFA) of Fe-based amorphous alloys. This study investigates the effects of ferromagnetic elements (Fe, Co, and Ni) on the microstructure and magnetic properties of Fe 86 B 7 C 7 amorphous alloys through experiments and ab initio molecular dynamics simulations. By analyzing both the experimental and simulation results, the relationship between the atomic structures, GFA, and magnetic properties of these amorphous alloys was determined. The results indicate that the GFA of the alloys is correlated with the proportion of icosahedral and body-centered cubic clusters. The addition of Co and Ni not only improved the GFA of the alloys but also effectively increased the overall magnetic moment with an appropriate amount of Co and a small amount of Ni. This increase in the magnetic moment primarily arises from the enhancement of the magnetic moment of Fe atoms, resulting from the redistribution between the spin-up and spin-down electrons of Fe-3 d orbits, as well as the strong exchange interactions between Fe and Co and Fe–Ni pairs. The results obtained offer valuable insights into the correlation between the atomic structure and magnetic properties of these amorphous alloys and suggest potential directions for the optimization of Fe-based amorphous alloys.