Effect of crystallization on soft magnetic properties of nanocrystalline Fe80B10Si8Nb1Cu1 alloy

The crystallization processes that occur in amorphous melt-spun ribbons of nominal composition Fe80B10Si8Nb1Cu1 during preparation and heat treatment affect the soft magnetic properties of this alloy. Fe80B10Si8Nb1Cu1 alloys are prepared by different quenching rates (wheel speeds of 10, 20 and 40 m/s) and their soft magnetic properties are studied. The XRD data reveal that as the wheel speed increases, the fraction of crystallinity and the Fe-Si grain size both decrease. These data also show that the sample prepared by the wheel speed of 10 m/s exhibits α-Fe particles on its free surface. The data for the samples prepared by the wheel speed of 20 and 40 m/s are in good agreement with the HRTEM images. VSM measurements show that these nanostructured samples exhibit coercivity in the range of 3-21 A/m and magnetic saturation in the range of 1.55-1.78 T.