Impedance Spectroscopy and Conduction Behavior in CoFe2O4-BaTiO3 Composites

Magnetoelectric composites combining ferromagnetic cobalt ferrite (CFO) and ferroelectric barium titanate (BT) are prepared using conventional solid-state reaction. Dielectric measurements reveal that CFO and CFO-BT composites exhibit Maxwell–Wagner polarization and temperature-dependent relaxation originating due to the presence of ions/defects vacancies. Prominently, CFO-30%BT composite showed an unexpected low dielectric loss ≈ 0.5 above 1 kHz and has potential for device application. Impedance spectroscopy confirms the thermally activated relaxation mechanism and high impedance behavior in the samples. Modulus analysis affirms the statistically distributed non-Debye-type behavior existing in CFO-BT composites. The electric conductivity takes place via correlated barrier hopping in CFO and CFO-10BT composite and overlapping large polaron tunneling in CFO-30BT composite. The addition of BT in CFO initiates the structural modification and results in conductivity cross-over with improved conductivity. These results are useful for exploring devices based on CFO-BT composites.