Effects of MoO/sub 3/ addition on manganese zinc ferrites

We examined the effect of added MoO/sub 3/ on the initial permeability and other material characteristics in order to develop Mn-Zn ferrites with a high permeability. It was found that although MoO/sub 3/ addition could expand the diameters of crystalline grains, it could also promote porosity, thereby impeding grain growth. When the amount of MoO/sub 3/ 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 MoO/sub 3/. Thus, we confirmed that high-permeability Mn-Zn ferrites could be obtained using a sintering technique which would enhance ferrite density.