Electrical and magnetic properties of NiCuZn–CaCu3Ti4O12 composites doped with Bi2O3

Bi2O3 was used to promote grain growth and to improve magnetic and dielectric properties of NiCuZn ferrite–CaCu3Ti4O12 composites during sintering. For a sintering temperature lower than 950 °C, the static permeability of the composites increases with the Bi2O3 content. Comparing with the composites without Bi2O3, the composite with Bi2O3 has a higher real permittivity and a lower loss tangent. With further increasing sintering temperature, it was found that the sample with 1 wt% Bi2O3 sintered at 1050 °C has the maximum static permeability, however, this was accompanied by an extremely high dielectric loss tangent. These results were analyzed in terms of the microstructures of the composites by scanning electron microscopy.