Effects of heat treatment on the structural properties and magnetic hyperfine parameters of Fe72Cr8Si8B12 amorphous ribbons

Fe-based amorphous alloys are extensively used in power electronics and other industries due to their high magnetic permeability, low coercivity and exceptional soft magnetic properties, which are closely related to their microstructure. In this study, the microstructure and hyperfine parameters of Fe72Cr8Si8B12 amorphous ribbons annealed at different temperatures were investigated using X-ray diffraction, scanning electron microscopy, Mössbauer spectrometry, and vibrating sample magnetometer. The results show that the crystallization process is due to the formation of α-Fe(Si), Fe2B and Fe23B6 phases. The measured 57Fe Mössbauer spectra were calculated by the superposition of several crystalline magnetic components for each annealing temperature (800, 825, 850 and 875 K), and the calculated values of the hyperfine fields for each component reflect a crystallization of the sample. Furthermore, the average nanograin size as well as the Curie temperature (TC) increase as annealing temperature increases. The simulation of the M(T) curve agrees well with the experimental data.