Investigation on magnetoelectric and dielectric properties of Co_0.9Mn_0.3Fe_1.8O₄–Sr_0.5Ba_0.5Nb₂O₆ composites

The present paper reports the dielectric and magnetoelectric properties of Mn substituted yCo_1.2−xMn_xFe_1.8O₄ (CMFO) and (1 − y) Sr_0.5Ba_0.5Nb₂O₆ (SBN) ME composites. The composites are formed with three weight percent of Bi₂O₃ as sintering aid. The Co_1.2−xMn_xFe_1.8O₄ is initially studied for variation of electrical resistivity ρ, saturation magnetization Ms, permeability μ, coercive field Hc and coefficient of magnetostriction λ to determine a composition suitable to form a ME composite. Here x = 0.3 is observed to posses optimal value of ρ, Ms, μ, Hc and λ, therefore the composites are formed using Co_0.9Mn_0.3Fe_1.8O₄. The composites y MSBN = y CMFO + (1 − y) SBN are synthesized and investigated for their structural, dielectric and magnetoelectric properties. The dielectric constant of composites is observed to exhibit contribution due to interfacial polarization as well as a contribution due to the SBN phase. The variation of linear magnetoelectric coefficient α and quadratic magneto electric coefficient β for varies compositions are reported in this paper. The paper also repots the effect of sintering temperature and variation of frequency on the magnitude of α and β. It is observed that the use of sintering aid increases the magnetoelectric output of the MSBN composites. The samples with y = 0.4 is observed to show sufficiently large and useful magnitude of magnetoelectric coefficients.