The effect of the microstructure on the DC-bias superposition characteristic of NiCuZn ferrite

The effects of combinational additive on the DC-bias superposition characteristic of NiCuZn ferrite were investigated experimentally. The composite NiCuZn ferrite was prepared by a conventional ceramic method. The sharp decrease of the permeability can be avoided when the magnetic field is small. It is because the permeability is mainly attributed to the χspin with fine grain size. Owing to the thicker nonmagnetic grain boundary, samples with good DC-bias superposition characteristic can be obtained by special combinational additions. Composite addition of Bi2O3, AlBSi glass, and SnO2 can both retard the grain growth and increase the thickness of the nonmagnetic grain boundary δ. Finally, an excellent performance sample was obtained. •We found that the decrease of permeability of mono-domain grains is much more slower under the DC-bias superposition magnetic field.•Good DC-bias superposition characteristic could be obtained by compound addition of Bi2O3, AlBSi glass and SnO2.•We gave a reasonable interpretation of the DC-bias superposition characteristic using the theory consisting of permeability.