The influence of Mn dopant on the electromagnetic properties of NiCuZn ferrite

In this paper, a citrate precursor method was used to prepare nano-sized NiCuZn ferrite powders with a composition of (Ni0.15Cu0.2Zn0.65O)(Fe2−xMnxO3+0.5x)0.99, (x = 0–0.04). Because of excellent sintering activity, the nanocrystals can be sintered below 900 °C without the addition of sintering aids. The effect of Mn dopant on the microstructures and the initial permeability was investigated. The results show that the introduction of Mn into NiCuZn ferrite has a great influence on its electromagnetic properties. The initial permeability of NiCuZn ferrite increases greatly with a small amount of Mn addition firstly, and then further increase of Mn content leads to a decrease in the initial permeability. By changing the content of Mn addition, the useful frequency dependence of initial permeability could be adjusted in a range of frequency from several hundreds of kilohertzs to several megahertzs.