Magnetic permeability and microstructure of the Bi,Si oxides-doped NiZnCu ferrite composite material

Bi,Si oxides-doped NiZnCu ferrite composite material has been fabricated with different sintering times. The microstructure of the samples was investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The complex permeability has been measured up to 1 GHz by the impedance analyzers. The complex permeability has been simulated based on the magnetic circuit model, and the result was compared with the experimental results. In the low-frequency region, the real part of the permeability of the composite material is lower than the one of non-doped NiZnCu ferrite, on the other hand it is higher than non-doped sample in the high-field region. The peak position of the imaginary part is shifted to higher frequency in the composite material.