Enhanced thermal-operating stability of high-frequency magnetic behavior for FeMnSiBNbCu nano-structural cores via field-annealing

Improving thermal-operating stabilization of soft-magnetic performances for Fe-based amorphous and nanocrystalline materials is vital for reliable and functional application. Herein, we found that the transverse magnetic-field annealed Fe74Mn2Si13B8Nb2Cu1 nano-structural alloy with an uniaxial anisotropy has negligibly unchanged distribution and grain size of α-Fe(Si) nano-grains and magnetic domain structure during thermal-operating, thus existing an excellent thermal-stability of magnetic properties. Its permeability at 100 kHz and core loss at 0.2 T and 100 kHz in the operating temperature of 160 °C increases 2.8% and decreases 3.5% with respect to that at room temperature, respectively, which is largely different from that of the normal-annealed alloys with only effective random anisotropy. The magnetic structure characterization demonstrates local induced anisotropy energy created with thermal-operating is suppressed by the magnetic-field induced anisotropy energy, leading to the enhancement of thermal-operating stability for nano-structural alloys with high magnetic induction via magnetic-field annealing.