Co2O3 and SnO2 doped MnZn ferrites for applications at 3–5 MHz frequencies

Abstract The rapid advancement of modern electronic technology requires MnZn ferrites capable of handling high-frequency signals, offering very low power loss and reasonably high permeability. MnZn ferrites were developed by using the conventional ceramic processing technique and the effects of Co2O3 and SnO2 doping on high-frequency magnetic properties were investigated. Co2O3 and SnO2 co-doping resulted in a sharp decrease of eddy-current loss and residual loss of the MnZn ferrites at 3–5 MHz and improved the temperature characteristics at 20–120 °C. The minimum power losses at 20 °C, 10 mT for 3 MHz and 5 MHz were 20 kW/m3 and 81 kW/m3, while the power losses at 100 °C, 10 mT for 3 MHz and 5 MHz were 60 kW/m3 and 205 kW/m3 respectively. The optimal saturation magnetic flux density and initial permeability were 480 mT and 675 respectively. The cut-off frequency of the sample was 12 MHz, establishing it as an ideal material for high-frequency applications.