Soft magnetic properties and loss performance of Co 2 O 3 -doped power MnZn ferrite at 100–300 kHz

In this study, a Co 2 O 3 addition from 0.28 to 0.44 wt% is added to the MnZn ferrites. The effects of Co 2 O 3 on the soft magnetic properties and loss performance of the MnZn ferrites were investigated over a wide temperature range from 25 to 140 °C. Either the spinel crystal structure or microstructure of the MnZn ferrites is not greatly affected by the Co 2 O 3 content. The saturation magnetic induction ( B s ) shows a maximum of 528 mT at 0.36 wt% Co 2 O 3 due to the slight increase in density. At room temperature, the initial permeability ( µ i ) of the MnZn ferrite is enhanced to a maximum of 2692, which is associated with the minimum magnetic anisotropy (| K| ) obtained at 0.36 wt% Co 2 O 3 . However, the DC resistivity of the MnZn ferrite is seen to decrease with increasing Co 2 O 3 content. Due to the enhanced initial permeability, the minimum core loss of the MnZn ferrite is obtained at 0.36 wt% Co 2 O 3 under various conditions from 100 kHz/200mT to 300 kHz/100mT.