Effects of TiO2 and Co2O3 combination additions on the elemental distribution and electromagnetic properties of Mn–Zn power ferrites

• TiO2 addition can promote Co2O3 transfer from grain boundaries to the bulk of grains.
• The Co2+ ion addition has a compensation for the effect of Ti4+on the Mn–Zn ferrites.
• The combination of TiO2 and Co2O3 additions insures stabilization of crystal lattice.
• The lowest power loss PL as 286 kW/m3 is relatively lower than reported now.

The effects of TiO2 and Co2O3 combination additions on the elemental distribution and electromagnetic properties of Mn–Zn power ferrites are investigated. TiO2 addition can promote Co2O3 transfer from grain boundaries to the bulk of the grains. The temperature at which the highest initial permeability μi and the lowest power losses PL appear shifts to low temperature range with the increase of Co2O3 content. Compared with the reference sample without TiO2 and Co2O3 addition, the microstructure and electromagnetic properties of Mn–Zn power ferrites can be considerably improved with suitable amounts of TiO2 and Co2O3 combination additions. At the peak temperature, the sample with the 0.1 wt% TiO2 and 0.08 wt% Co2O3 additions has an increase of 15.8% in μi to 3951, and a decrease of 22.9% in PL to 286 kW/m3. The saturation magnetic induction Bs and electrical resistivity ρ at 25 °C reach the highest values of 532 mT and 8.12 Ω m, respectively.