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. - Highlights: • The magnetic properties of Mn–Zn ferrites doped with nano-TiO2 were investigated. • With the content of nano-TiO2 increasing, the magnetic properties increase. • The power loss (PL) of the sample doped with 0.07 wt% normal-size TiO2 is 315 kW/m3. • And the PL of the sample is lower than 330 kW/m3 at the range of 90–120 °C