We examined the effect of added MoO3 on the initial permeability and other material characteristics in order to develop Mn-Zn ferrites with a high permeability. It was found that although MoO3 addition could expand the diameters of crystalline grains, it could also promote porosity, thereby Impeding grain growth. When the amount of MoO3 was increased, the grain diameter expanded, peaked, and then gradually declined under the influence of porosity. However, by prolonging the top-temperature sintering period to curb porosity, it was possible to realize the grain-growth-promotion effect of MoO3. Thus, we confirmed that high-permeability Mn-Zn ferrites could be obtained using a sintering technique which would enhance ferrite density.
