Microstructure and electromagnetic properties of low-temperature sintered NiCuZn ferrite by co-doped Bi2O3 and Co2O3

In this work, the electromagnetic of NiCuZn ferrite was enhanced and the sintering temperature was decreased by co-doped Bi2O3 and Co2O3. The influence of the doping concentration of Co2O3 on the microstructure and magnetic properties of NiCuZn ferrite was studied. Characterizations display that the high density and uniform microstructure of NiCuZn ferrite was obtained at a low sintering temperature of 925 degrees C. The Co ions were doped in the octahedral B-sites and decreased lattice constant and grain size. The resistivity was also improved after doping appropriate Co ions for the decrease of the Fe2+. The saturation magnetization, coercivity, permeability, and cut-off frequency were also enhanced after being doped with the Co2O3. Consequently, the NiCuZn ferrite doped with 0.30 wt% Bi2O3 and 0.4 wt% Co2O3 possesses a saturation magnetization of similar to 60.014 emu/g, coercivity of similar to 0.033 kA/m, real part of permeability of similar to 269.9 @ 1 MHz, and high cut-off frequency of 8.08 MHz, which can be applied in multi-layer chip inductors.