Effect of TiO2 and Nb2O5 additives on the magnetic properties of cobalt-modified MnZn ferrites

Cobalt-modified manganese–zinc (MnZn) power ferrites with good thermal stability were prepared by conventional ceramic technique. The influences of TiO2 and Nb2O5 additives on the properties of cobalt-modified MnZn power ferrite were investigated. It was shown that moderate amount of TiO2 and Nb2O5 additives could increase the permeability and reduce the power loss effectively while keeping the better thermal stability of cobalt-modified MnZn ferrite. The best magnetic properties were obtained at addition amount of 0.03 wt% TiO2 and 0.02 wt% Nb2O5 with an initial permeability (µ i ) of 3200 at room temperature and power loss keeping below 400 kW/m3 from 20 to 100 °C. The related mechanisms were briefly discussed.