Structural, magnetic and impedance spectroscopy analysis of (0.7)CoFe2O4+(0.3)BaTiO3 magnetoelectric composite

Abstract Magnetoelectric composite of particular composition (0.7)CoFe2O4+(0.3)BaTiO3 was synthesized by ball-milling method. X-ray diffraction pattern confirmed the presence of cubic spinel phase for CoFe2O4 and the coexistence of tetragonal phase along with a small fraction of hexagonal phase for BaTiO3 in the prepared composite. The dielectric permittivity increased with increasing temperature (298–373 K); however, it showed relatively high magnitude of permittivity (∼1100) and diminished dielectric loss (∼0.045) at higher frequency. Complex impedance and modulus plots exhibited responses of different electro-active regions which are explained on the basis of coexistence of resistive and comparatively conductive phases in the prepared composite. Small polaronic hopping model was employed to explain the n-type carrier’s mobility as a possible conduction mechanism; whereas the activation energies calculated from the conduction and relaxation processes were found to be comparable. These results indicate that electric/dielectric properties and relaxation phenomenon are associated to the same origin.