Enhancement in the magnetoelectric and energy storage properties of core-shell-like CoFe2O4−BaTiO3 multiferroic nanocomposite

Abstract Herein we report the development of a core-shell-like Co Fe 2 O 4 − BaTi O 3 multiferroic nanocomposite (1:1 wt ratio) for their enhanced magnetoelectric coupling and energy storage density by the wet chemical route. Rietveld refinement analysis of the XRD pattern verified the formation of cubic spinel ( Co Fe 2 O 4 ) and tetragonal perovskite ( BaTi O 3 ) structures. Whereas the SEM and EDX analysis confirmed the formation of core-shell-like morphology in the composite. The temperature dependence of dielectric permittivity showed two distinct peaks corresponding to the constituent phases´ structural phase transitions. However, the frequency dependence of low-temperature peak revealed an abnormal relaxor-type behavior, which is elucidated due to intrinsic structural defects that might cause alteration in the octahedron arrangement in BaTi O 3 . Impedance spectroscopy analysis was utilized to calculate the activation energy (Ea) of respective phases, which was found to be>1 eV that confirms the dominance of doubly ionized oxygen vacancies in governing the thermally stimulated conduction process. It was found that the prepared composite exhibited high dielectric permittivity (~2700) and moderate values of saturation magnetization (20 emu/g) and polarization (6.2 μC/cm2) along with low remnant polarization (3 μC/cm2) at room temperature. Moreover, we also observed enhanced energy storage efficiency (67%) and magnetoelectric coefficient (0.18 V/cm Oe), which are explained due to strong interfacial coupling and reduced leakage current, making this composition promising for multifunctional device applications.