High saturation magnetic flux density of Novel nanocrystalline core annealed under magnetic field

In the present study, the magnetic and microstructural properties were investigated of Fe-based nanocrystalline soft magnetic alloy with the composition of Fe80Si7B9Nb3Cu1 fabricated by the melt-spinning method. The annealing under varying transverse magnetic field was applied to induce the uniform distribution of α-Fe nanocrystals. The lowest core loss (Pcv) was 124.0 mW/cm3 achieved with the specimen annealed at 560 °C. Furthermore, the core annealed at 560 °C showed the Bs as high as 1.57 T which is significantly higher than that of conventional FINEMET core (Bs = 1.23 T). The combination of high Bs with excellent magnetic properties makes this nanocrystalline alloy a promising candidate for the application in high frequency (f) region. •The nano-crystalline alloy exhibited exceptionally good soft magnetic properties compared to the typical value of FINEMET core by magnetic field annealing.•The nano-crystalline core has α-Fe nanoparticles embedded in an amorphous phase.•The observed microstructure properties are corresponded with the Scherrer formula.