Investigation on magnetoelectric and dielectric properties of Co_(0.9)Mn_(0.3)Fe_(1.8)O_4-Sr_(0.5)Ba_(0.5)Nb_2O_6 composites

摘要

The present paper reports the dielectric and magnetoelectric properties of Mn substituted yCo_(1.2-x)Mn_x Fe_(1.8)O_4 (CMFO) and (1 - y) Sr_(0.5)Ba_(0.5)Nb_2O_6 (SBN) ME composites. The composites are formed with three weight percent of Bi_2O_3 as sintering aid. The Co_(1.2-x)Mn_xFe_(1.8)O_4 is initially studied for variation of electrical resistivity p, saturation magnetization Ms, permeability μ, coercive field He 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 p, Ms, μ, He and λ, therefore the composites are formed using Co_(0.9)Mn_(0.3)Fe_(1.8)O_4. 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 a and quadratic magneto electric coefficient fi 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 a and /i. 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.