Effects of annealing temperature on the structure characteristics of Fe83Si6B6Cu1Nb1P1.5C1.5 amorphous ribbons

As an excellent soft magnetic material with high magnetic permeability and low coercivity, Fe-based amorphous alloys are widely applied in power electronics and other fields, which greatly depend on its microstructure. In the current work, the microstructure and magnetic properties of Fe83Si6B6Cu1Nb1P1.5C1.5 amorphous ribbons annealed at different temperatures were systematically studied by X-ray diffraction (XRD) and atom probe tomography (APT). Results reveal that the alpha-Fe(Si) nanocrystalline phase preferentially nucleates on the surface of the pre-precipitated Cu clusters, which promotes the nucleation rate of alpha-Fe(Si) grains, by providing heterogeneous nucleation sites. The amorphous forming elements of B, P, and C elements exist around alpha-Fe(Si) phase in the forms of residual amorphous, forming a core-shell structure, which confined the growth of nanocrystalline alpha-Fe(Si) grains at high temperature. The optimum saturation magnetization with the highest value of the ribbons is up to 184.25 emu/g for samples annealed at 550 degrees C for 30 min.