Effects of nano-TiO2 and normal size TiO2 additions on the microstructure and magnetic properties of manganese-zinc power ferrites

The effects of nano-TiO2 and normal size TiO2 additions on the microstructure and magnetic properties of manganese-zinc (Mn-Zn) power ferrites were investigated, respectively. It is found that the magnetic properties of Mn-Zn power ferrites can be improved with a suitable amount of nano-TiO2 or normal size TiO2 addition. At 100 °C, compared to the reference sample without nano-TiO2 addition, the sample with 0.05 wt% nano-TiO2 addition shows a more uniform grain structure and a decrease of 9.63% in power loss (PL) to 394 kW/m3. In this case, the initial permeability of sample declines by 0.3%, compared to that of the sample with 0.03 wt% nano-TiO2 addition. Besides that, at 100 °C, when the normal size TiO2 concentration increases gradually to 0.07 wt%, the PL of sintered samples decreases monotonously to 315 kW/m3. In the temperature range of 90-120 °C, the PL of the sample with 0.07 wt% normal size TiO2 addition are lower than 330 kW/m3. It is indicated that the optimal content of normal size TiO2 is higher than 0.07 wt%. The thermal stability of sintered sample can be considerably improved with a suitable amount of nano-TiO2 or normal size TiO2 addition.