AC conductivity and magnetoelectric effect in MnFe1.8Cr0.2O4–BaTiO3 composites

Magnetoelectric composites with composition xBaTiO3+(1−x)MnFe1.8Cr0.2O4 in which x varies as 1, 0.85, 0.7, 0.55 and 0 were prepared by a standard ceramic technique. X-Ray analysis confirms single-phase formation in x=1 and x=0 compositions whereas the presence of both phases in x=0.85, 0.7 and 0.55 compositions. The dielectric constant (ε′), loss tangent (tan δ) and AC conductivity (σAC) of the composites have been investigated in the frequency range 100 Hz–1 MHz and also in the temperature range 30–400 °C. The results obtained are interpreted in terms of a polaron hopping mechanism. Static magnetoelectric conversion factor (dE/dH) as a function of magnetic field was measured in x=0.85, 0.70 and 0.55 compositions. The maximum value of dE/dH obtained was 150 μV/(cm−1×Oe) for x=0.85 composition.