Effect of Cation Distribution and Structural Properties on Permeability of Ni-Mg Ferrite with Li 2 CO 3 Additive

The structural properties and permeability of polycrystalline Ni 0.6 Mg 0.4 Fe 2 O 4 ferrite are studied with the addition of Li 2 CO 3 at 0%, 2%, 4%, and 6%. The samples were synthesized by the conventional ceramic method at 1300C sintering temperature for 6 hours. X-ray diffraction method is applied to understand the crystal structure of the following ferrite and it is confirmed that the samples have absolute single phase cubic spinel structure. The lattice constant of the ferrite varies with the increasing of Li 2 CO 3 content. The microstructure analysis of the samples is carried out by SEM micrographs. From SEM images it is observed that the ferrite is in regular in shape and the grains are well connected with each other. The average grain sizes of the sample increased with increasing Li 2 CO 3 content. Crystalline size of the sample follows the same manner of grain size of the samples. The Curie temperature is measured by using inductance analyzer. Curie temperature increased at 2% addition of Li 2 CO 3 and the further increase in Li 2 CO 3 leads to decrease in the Curie temperature whereas permeability shows just opposite attitude of Curie temperature in this study. Complex permeability and relative quality factor are also measured as a function of temperature and frequency respectively.