Improved soft magnetic properties of FeSi/FeSiCrBC compound powder core induced by enhanced magnetic coupling

We report the improved soft magnetic properties of FeSi powder core (PC) by doping an appropriate amount of fine FeSiCrBC amorphous powder into the air gaps between the triple-junction structures of coarse FeSi powder. Resultantly, the addition of FeSiCrBC powder, which has a lower permeability (μe) and higher hardness relative to FeSi powder, does not lead to a decrease in the μe of the FeSi/FeSiCrBC compound PC (CPC) with the reduced porosity but rather yields an increase. Rationally, this is attributed to the enhanced magnetic coupling in the CPC, which is compared with the corresponding ones with FeSi or FeSiAl PCs. Meanwhile, the core loss of the CPC reduces significantly. This is due to the decreased non-uniform magnetization regions in the CPC with proper content FeSiCrBC addition. The results herein can provide a novel strategy for fabricating PCs used in new-generation high-properties and miniaturized inductors.