Effect of MoO3 Addition on the Grain Growth Kinetics of a Manganese Zinc Ferrite

The effect of MoO₃ addition on the grain growth and densification kinetics of a high permeability manganese zinc ferrite was studied. Grain growth in the presence of a small amount of MoO₃ occurs in two main stages characterized by a faster rate of grain growth accompanied by rapid densification and pore coalescence in the first stage, when the MoO₃ is present as a liquid phase along the grain boundaries, and comparatively slower rates of grain growth and densification than those for the basic composition in the second stage, when MoO₃ evaporates from the matrix. The activation energies for grain growth in these stages suggested that surface and volume diffusion mechanisms were operating in the first and second stages respectively.