Structural, Magnetic, Dielectric and Energy Storage Analysis of CoFe2O4@BaTiO3 and BaTiO3@CoFe2O4 Core-Shell Nano- Composites

Abstract Nano size spinel ferrite CoFe2O4 (CFO), ferroelectric BaTiO3 (BTO) and their core-shell nanocomposites BTO@CFO and CFO@BTO were synthesized using combination of chemical co-precipitation and sol-gel route respectively. The phase formation and crystallinity of bare CFO, BTO and their core-shell nanocomposites were verifiedviaX-ray diffraction pattern (XRD). High resolution transmission electron microscopy(HRTEM) revealed the core-shell structure of the nanocomposites.Magnetization measurements exhibitferromagnetic behaviour of all the samples except BTO in which superposition of weak ferromagnetic and diamagnetic response occurred due to its nanostructure. Magnetization versus temperature (M-T plot) measurements show anomaly near ferroelectric to paraelectric phase transition of BTO. Also,dielectric constant(ε¢) and tangent loss (tanδ) variation with respect to frequency (102 to 106 Hz) and temperature (300-700 K) were presented. ε¢-T curve of nanocomposites exhibit anomaly at the same temperature as observed in M-T plot of nanocomposites that indicate the inherent magneto-electric coupling in nanocomposites. Energy storage properties of BTO and nanocomposites have been examined via P-E loop analysis and confirmed that the sample CFO@BTO exhibit maximum energy storage efficiency.