Influence of field-induced anisotropy on magnetic properties and domain structure of Fe-based nanocrystalline alloy via a new continuous magnetic field annealing furnace

The high-frequency magnetic properties correlated with field-induced anisotropy ( K u ) and domain structure of Fe-based magnetic cores treated using transverse magnetic field in situ crystallization annealing (TFA) with different applied intensities ( H a ) via a new continuous magnetic field annealing furnace have been systematically studied comparing with those annealed without magnetic field (NA). The enhancing H a can cause increases of K u and domain wall energy, thus leading to the inclination of hysteresis loop and the reduction of permeability ( µ ) at low frequency. As compared to the optimal NA core annealed at 798 K, the µ at 50 and 100 kHz separately increase by 229.3% and 254.9% to 65,800 and 41,300, while the core loss at 0.2 T and 100 kHz decreases by 49.3% to 16.38 W/kg for the TFA core treated at H a = 0.12 T. Herein, the TFA ~ 0.12T sample with K u /< K 1 > ~ 1.09 induced the magnetization rotation together with domain splitting and motion dominating in the magnetization process and the relatively high active domain wall density, giving rise to the improved high-frequency properties, compared with the NA sample has only < K 1 > ~ 4.5 J/m 3 . This work offers a feasible way to improve high-frequency magnetic properties to meet the minimization and high-efficiency demands of electronic devices by in situ TFA process.