Magnetic Properties of Highly Permeable MnZn Ferrite.

The effect of the microstructure and oxygen content of sintered MnZn ferrite on the initial permeability was investigated in order to achieve high initial permeability. It is shown that discontinuous grain growth causes not only non-uniformly sized grain structure but also intragrain impurities, and has a deleterious effect on the initial permeability. The initial permeability is also a function of the oxygen content of sintered MnZn ferrite. Bi2O3 doping is effective for reducing the difference in oxygen content between the inner and outer parts of a sintered body. As a result of this investigation, we have developed MnZn ferrite with high initial permeability.