Glass-Forming Ability and Crystallization Behavior of Mo-Added Fe82−xSi4B12Nb1MoxCu1 (x = 0–2) Nanocrystalline Alloy

This study investigates the effects of molybdenum (Mo) additions on the crystallization behavior and soft magnetic properties and of Fe82-xSi4B12Nb1MoxCu1 (x = 0–2) nanocrystalline alloys. Molybdenum enhances glass-forming ability (GFA) and magnetic properties by increasing negative mixing enthalpy (∆Hmix), mixing entropy (∆Smix), and atomic size mismatch (δ), which stabilize the amorphous phase. X-ray diffraction (XRD) analysis shows that Mo addition improves amorphous phase stability, further enhancing GFA. The simultaneous addition of Mo and Nb increases mixing entropy, promotes nucleation rates, and creates favorable conditions for optimizing nanocrystallization. Upon annealing, this optimized microstructure demonstrated low coercivity and high permeability. Notably, the Fe80Si4B12Nb1Mo2Cu1 ribbon, annealed at 470 °C for 10 min, exhibited exceptional soft magnetic properties, with a coercivity of 4.54 A/m, a maximum relative permeability of 48,410, and a saturation magnetization of 175.24 emu/g. High-resolution transmission electron microscopy (TEM) revealed an average crystal size of 18.16 nm. These findings suggest that Fe82-xSi4B12Nb1MoxCu1 (x = 0–2) nanocrystalline alloys are suitable for advanced electromagnetic applications pursuing miniaturization and high efficiency.