Study of the effects of metalloid elements (P, C, B) on Fe-based amorphous alloys by ab initio molecular dynamics simulations

In order to understand the effects of the metalloid elements M (M: P, C, B) on the atomic structure, glass formation ability (GFA) and magnetic properties of Fe-based amorphous alloys, Fe₈₀P₁₃C₇, Fe₈₀P₁₄B₆ and Fe₈₀B₁₄C₆ amorphous alloys are chosen to study through first-principle simulations in the present work. The atomic structure characteristic of the three amorphous alloys is investigated through the pair distribution functions (PDFs) and Voronoi Polyhedra (VPs) analyses. The PDFs and VPs analyses suggest that the GFA of the three alloys dropped in the order of Fe₈₀P₁₃C₇, Fe₈₀P₁₄B₆, and Fe₈₀B₁₄C₆, which is well consistent with the experimental results. The density of state (DOS) of the three amorphous alloys is calculated to investigate their magnetic properties. Based on the DOS analysis, the average magnetic moment of Fe atom in Fe₈₀P₁₃C₇ and Fe₈₀P₁₄B₆ amorphous alloys can be estimated to be 1.71 μ_B and 1.70 μ_B, respectively, which are in acceptable agreement with the experimental results. However, the calculated average magnetic moment of Fe atom in Fe₈₀B₁₄C₆ amorphous alloy is about 1.62 μ_B, which is far less than the experimental result