Comparative study of magnetoelectric composite system Ba0.95Sr0.05TiO3-Ni0.8Co0.2Fe2O4 with ferrite prepared by different methods

In this paper, effect of addition of Ni0.8Co0.2Fe2O4 (NCF), prepared by three different methods namely solid state reaction method, sol-gel and co-precipitation, has been studied on microstructural, magnetic, dielectric, ferroelectric and magnetoelectric properties of multiferroic composite system 0.95 Ba0.95Sr0.05TiO3-0.05 Ni0.8Co0.2Fe2O4. Ba0.95Sr0.05TiO3 (BST) has been prepared by solid state reaction method. Titular representation of NCF samples prepared by sol-gel, co-precipitation, solid state reaction method is N-SG, N-CP, N-SS respectively and that of corresponding magnetoelectric composite is C-SG, C-CP, C-SS. X-ray diffraction analysis of the composite samples (C-SG, C-SS, C-CP) indicated the presence of both NCF and BST phases. Rietveld analysis of XRD pattern further confirmed the proper phase formation in the composite samples. Sol-gel and co-precipitation processes result in finer NCF particles as confirmed by Transmission electron microscopy (TEM). Sample N-SG possesses uniform particle size and shape. Magnetization versus magnetic field (M-H) loops of samples C-SS and C-CP possess respectively highest value of remanant magnetization and magnetic coercive field. Dielectric properties of BST, NCF and composite samples have been measured in the frequency range of 20 Hz-1 MHz and temperature range of 50-170 °C. The composite sample C-CP results in highest value of dielectric constant in comparison to samples C-SS and C-SG. Polarization versus electric field (P - E) measurements pointed that composite sample C-SG possesses highest value of remanant and saturation polarization and C-SS possesses lowest value of coercive electric field. The composite sample C-SS possesses highest value of magnetoelectric coefficient.