Electric and Magnetic Properties of Ta-Doped Polycrystalline Mn-Zn Ferrite

Abstract
The effect of Ta2O5 additive on the electric and magnetic properties of MnZn ferrites with fine grain size was studied. A adding small amounts of Ta2O5 to the MnZn ferrite increased electric resistivity, while an excessive addition of Ta2O5 caused decrease in resistivity without significant grain growth. In a small amount of Ta2O5 the change in the electric resistivity can be explained by Ta⁵⁺ substitution for Fe³⁺ entailing disappearance of the oxygen defects. The excessive addition of Ta2O5 created the oxygen defects and the electrons which are promoted by the metallic ion defects and the thermal dissociation of oxygen.