Structural relaxation and magnetic properties of multicomponent Fe‐based amorphous alloy ribbons

Abstract Fe‐based amorphous alloy ribbons Fe 65 Co 15 Si 5 B 15 and Fe 73.5 Si 13.5 Nb 3 B 9 Cu 1 were fabricated using single‐roller melt spinning. Thermodynamic analysis revealed comparable glass transition ( T g ) and crystallization ( T x ) temperatures for both alloys. Calculations of mixing enthalpy and entropy demonstrated that Fe 73.5 Si 13.5 Nb 3 B 9 Cu 1 exhibits more pronounced β‐relaxation behavior at lower temperatures, attributable to enhanced atomic motions as evidenced by dynamic mechanical analysis (DMA) and pair distribution function (PDF) studies. Furthermore, the magnetization of Fe 73.5 Si 13.5 Nb 3 B 9 Cu 1 declines more rapidly with increasing temperature, indicating that its magnetic properties are more susceptible to temperature. Although both alloy ribbons exhibit similar temperature transitions, the quinary alloy ribbon demonstrates more pronounced relaxation and heightened temperature sensitivity. Therefore, precise control of the relaxation and crystallization behavior is particularly important to achieve excellent soft magnetic performance in multicomponent amorphous ribbons.