Effects of TiO_2 and Co_2O_3 combination additions on the elemental distribution and electromagnetic properties of Mn-Zn power ferrites

摘要

The effects of TiO_2 and Co_2O_3 combination additions on the elemental distribution and electromagnetic properties of Mn-Zn power ferrites are investigated. TiO_2 addition can promote Co_2O_3 transfer from grain boundaries to the bulk of the grains. The temperature at which the highest initial permeability μ_i and the lowest power losses P_L appear shifts to low temperature range with the increase of Co_2O_3 content. Compared with the reference sample without TiO_2 and Co_2O_3 addition, the microstructure and electromagnetic properties of Mn-Zn power ferrites can be considerably improved with suitable amounts of TiO_2 and Co_2O_3 combination additions. At the peak temperature, the sample with the 0.1 wt% TiO_2 and 0.08 wt% Co_2O_3 additions has an increase of 15.8% in μ_i to 3951, and a decrease of 22.9% in P_L to 286 kW/m~3. The saturation magnetic induction B_s and electrical resistivity ρ at 25 ℃ reach the highest values of 532 mT and 8.12 Ω m, respectively.