Correlation between dynamic magnetization process and dynamic domains of high saturation induction FeSiBNbCuMo nanocrystalline alloy with dual anisotropies

Abstract Improving the high-frequency properties of the relatively high saturation induction alloys is significance for widening the frequency range of the noise suppression of common mode chokes. Herein, transverse magnetic field annealing after having been nano-crystallized (TA) was performed to the as-quenched Fe76Si13B8Nb1.5Cu1Mo0.5 alloy, and the dynamic properties, microstructure, and dynamic domains were in detail studied comparing with those annealed without magnetic field (NA). It was found that TA at 400 oC caused an increase in permeability at 50 kHz by 41% and a decrease in core loss at 0.2 T and 50 kHz by 30%, in comparison with those of NA. TA at 400 oC induced the ratio of field induced anisotropy constant Ku to average random anisotropy constant to be ~ 1.3 and inhomogeneous rotation, leading to the promoted domain refinement with increasing frequency and improved high-frequency properties, compared with that of NA bears only ~ 5.4 J/m3. Moreover, the role of dual anisotropies on the magnetic domain structures, dynamic magnetization process and magnetic performances were obtained and its correlation model based on the experimental results was established. These results could provide a good guide for performance optimization to meet higher frequency requirements of common mode chokes application.