Structural and dielectric studies of cobalt ferrite nanopowder prepared by ceramic method

Cobalt ferrite {Cox(Fe2O3)1-x} samples were prepared by conventional ceramic method with ferrite system (x = 0.29, 0.31, 0.33 and 0.35). Structural measurements showed that all the samples of (CoFe2O4) have spinel phase structure. The other phase which has been observed belongs to (α-Fe2O3). The structural parameters such as interplanar distance (d), lattice constant (a) and grain size (D) have been evaluated. X-Ray diffraction patterns showed that the crystal growth became stronger and more oriented and grain size became larger with increasing (Co) ratio. Dielectric measurements, A.C conductivity (σa.c), dielectric constant (ε'), and dielectric loss tangent (tanδ) were measured in the frequency range (103Hz to 5MHz) at room temperature. All the samples show the normal dielectric dispersion. The dielectric constant (ε') has a decreasing nature with frequency. This behavior is explained qualitatively in terms of the supposition that the mechanism of the polarization process in ferrite is similar to that of the conduction process.