STRUCTURE AND CHARACTERIZATION OF BaTiO3-Ni(1-x)Zn(x)Fe2O4 COMPOSITES

Abstract

NiZnFe2O4 (NZF) powder was prepared by auto-combustion method starting from nickel, zinc and iron nitrates. Thermal treatment was performed at 1000 oC for 1 h after which the nickel ferrite powder was formed. Barium titanate (BT) powder was prepared with same method using titanyl nitrate and barium nitrate as a starting reagents. Multiferroic composites with formula BaTiO3– Ni(1-x)ZnxFe2O4 (x = 0.3, 0.5, 0.7) were prepared by mixing chemically obtained NZF and BT powders in the planetary mill for 24 h. Powders were pressed and sintered at 1170 oC for 4 h. Samples were characterized by XRD, Raman, SEM, IR. Magnetic and electrical measurements were also carried out. X-ray and Raman measurements confirmed the presence of NZF, BT phases and the traces of barium ferrite phase. The microstructure of the ceramics shows (Fig. 1.) the formation of polygonal (NZF grains), rounded (BT grains) and plate like grains (barium ferrite phase). The impedance analyses of multifferoic composites at 200 ºC have shown the contribution of both, grain and grain boundary resistivity.