Effects of CuO、 MoO3 and WO3 dopping on magnetic properties of NiZn ferrites
Effects of CuO、MoO3 and WO3 dopping on magnetic properties of NiZn ferrites

The effects of CuO, MoO3 and WO3 on the magnetic properties of NiZn ferrites were investigated. The results showed that proper CuO doping could increase bulk density and decrease anisotropy constant of the NiCuZn ferrite samples, so the initial permeability increased. But the Curie temperature decreased in a certain extent. 4%(molar fraction) CuO content could farthest give attention to high initial permeability and high Curie temperature demand of the NiCuZn ferrites. The Effects of MoO3 and WO3 doping on magnetic properties of the NiZn ferrites were also investigated. It was found that both of them could increase metallic ion vacancies in the grain boundary region; as a result, the speed of the grain boundary movement increased, thereby promoting grain growth. Consequently, the initial permeability of samples increased. Tungsten ions also had a stronger preference of tetrahedral site of ferrites and could partially substitute ferric ions, so more WO3 content was necessary to obtain highest initial permeability, Curie temperature and saturation magnetism of WO3 added samples were also lower than that of MoO3 added samples.