Magnetoelectric and magnetodielectric effect in CFMO-PBT nanocomposites

The present paper reports the dielectric, magnetoelectric (ME) and magnetodielectric (MD) properties of Co1.2Fe1.8−xMnxO4 (CFMO) and Pb0.2Ba0.8TiO3 (PBT) composites. The CFMO 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=0.1 is observed to be suitable composition therefore the composites are formed using Co1.2Fe1.7Mn0.1O4 (CFMO). The composites y CMPBT=(y)CFMO+(1−y)PBT are synthesized and investigated for their structural, dielectric, magnetoelectric, magnetodielectric properties and variation of magnetoresistance with H. The dielectric constant of composite is observed to exhibit contribution due to interfacial polarization as well as a contribution due to the PBT ferroelectric phase. The variation of linear magnetoelectric coefficient α and quadratic magneto electric coefficient β for various compositions are reported in this paper. The paper also reports the effect of sintering temperature and variation of frequency on the magnitude of α and β. The composite with higher value of β is investigated also for the magnetodielectric property and it is observed that the composite with y=0.5 shows useful value of magnetocapacitance (Mc).

► The CFMO and PBT are synthesized by hydroxide co-precipitation method.
► Successful synthesis of CMPBT composite is reported.
► A magnetoelectric property of composites depends on the sintering temperature.
► The positive and negative magnetocapacitance depend on the magnetic field.