LAUSR

Abstract In the present study, we investigated the effect of heat treatment on the magnetic properties of the Fe87-xSixB9Nb3Cu1 (x = 1, 3, 5, 7, 9, and 13.5) alloy system. Ribbon samples with the width of 2 mm and thickness of 20–30 μm were synthesized by melt spinning. Among the samples, only amorphous samples were nanocrystallized by annealing between 360 and 600 °C. The annealed alloys tended to have improved soft magnetic characteristics, including higher saturation magnetic flux density (Bs), while maintaining high relative permeability ( μ r ) , and low core loss (Pcv). A high saturation magnetic flux density of 1.51 T was obtained for the Fe78Si9B9Nb3Cu1 core sample after longitudinal magnetic field annealing at 520 °C. The sample had excellent soft magnetic properties as compared to the conventional value of FINEMET core (Bs = 1.23 T), which is a significant improvement as compared to the as-spun ribbons (Bs = 1.10-1.26 T).