Enhanced magnetic performance of soft magnetic composites with a synergistic hybrid insulation of Cr-O and (Ni,Zn)Fe2O4

With the rapid advancement of power electronics toward high-frequency and miniaturization, there is an urgent demand for soft magnetic composites (SMCs) that possess both high permeability and low core loss. Herein, a novel Cr-O&(Ni,Zn)Fe 2 O 4 synergistic hybrid insulation was synthesized on FeSiBCCr amorphous powders via sequential hydrothermal and chemical co-precipitation methods. The oxygen partial pressure during annealing was optimized using 0.8 wt.% carbon powder to enhance the crystallinity and magnetic properties of the ferrite insulating coating. The resulting SMCs exhibited a saturation magnetization ( M s ) of 140.0 emu/g and an effective permeability ( μ e ) of 35.03. Notably, the core loss P 50mT/1MHz was reduced to 2143.10 mW/cm 3 , which is 50.72% lower than that of the core sample prepared by using raw powder without ferrite insulating coating. This synergistic hybrid insulation effectively suppresses inter-particle eddy currents and reduces domain wall pinning, offering a high-performance solution for high-frequency power electronics.