Fluctuations of the Local Atomic Environment with Chemical Alloying in Fe Bulk Metallic Glasses

Fluctuations in the microstructure with chemical alloying of Fe multicomponent bulk metallic glasses were characterized via the pair density function analysis of neutron diffraction data. In the two systems investigated, (Fe/Mo)₇₆P₁₂C₁₀B₂ and Fe₄₉Cr₁₅Mo₁₄Er₁(C/B)₂₁, it is shown that the atomic topology is sensitive to even small chemical fluctuations. In phosphorous containing glasses, (Fe/Mo)₇₆P₁₂C₁₀B₂, increasing the atomic percent of Mo brings about changes of the microstructure, particularly in the short-range environment involving Mo-C/B and Fe-P pair correlations. In Fe₄₉Cr₁₅Mo₁₄Er₁(C/B)₂₁, the systematic increase of B results in a shift of the center of mass of the first coordination shell and an increase in the coordination of the second shell, reflecting a local rearrangement brought upon the substitution of B for C.