Magnetodielectric properties of CoFe2O4-BaTiO3 core-shell nanocomposite

The magneto-electric (ME) and multiferroic CoFe2O4 (CFO)/BaTiO3 (BTO) core-shell nanocomposite is prepared by co-precipitation followed by citrate-gel method. The XRD patterns indicate that the magnetic CFO phase is compatible with the ferroelectric BTO phase. The core-shell nature with homogeneous mixing of magnetic and dielectric phase is confirmed by microstructural analysis. The magnetic and ferroelectric phase preserves their basic individual properties in the core-shell form. The magnetodielectric (MD) response of the nanocomposite is attributed to magnetostriction of CFO at low frequencies, and at high frequencies is due to magnetostriction and the magnetoresistance effects. The Maxwell-Wagner effect combined with the magnetoresistance (MR) is dominant at the intermediate frequencies. The ME coupling susceptibility of the sample was indirectly derived through the MD measurements by eliminating the combined 'Maxwell-Wagner and the magnetoresistive effects'. ME coupling susceptibility of 0.6±0.2 mV/cm Oe is obtained indirectly by MD measurements at room temperature upto a maximum field of 7 kOe. The observed MD effects are attributed to the presence of magnetostrictive and magnetoresistive behavior of core-shell nanocomposite.