Magnetoelectric Effect in Multiferroic CoFe2O4-BaTiO3 Composites

Abstract

Co1-xFe2+xO4-2BaTiO3 (x=0, 0.1 and 0.2) samples were prepared by using a conventional ceramic method. X-ray diffraction (XRD) and electron probe micro analysis (EPMA) measurements were done on these samples and we confirmed that cobalt ferrite and BaTiO3 components were clearly separated in the composites. The samples exhibited both ferroelectric and ferromagnetic properties. This indicates the samples were multiferroic materials. The resistivity was increased with x, whereas the tetragonality of BaTiO3 was decreased with x. While a sample with x=0.1 had the highest permittivity of 522, samples with x=0 and 0.2 had lower permittivity, which may have been caused by leakage current and deterioration of the ferroelectricity of BaTiO3, respectively. This same sample with x=0.1 also exhibited the highest ME coefficient of 0.2 mV/cm Oe. We expect that improved permittivity will lead to a higher ME coefficient.