Investigation of multiferroic properties in nickel ferrite -barium titanate nanocomposites at room temperature

Abstract

Nano composites of xNiFe2O4 – (1-x) BaTiO3 (x = 0.2, 0.3 and 0.4) were synthesized by solid state reaction method. The crystal structure was confirmed by XRD and Raman spectra at room temperature. Magnetic hysteresis behaviour exhibits well saturated ferromagnetic hysteresis loops. The retentivity (Mr) of the composites 20:80, 30:70 and 40:60 are 1.04 emu/g, 1.71emu/g and 3.40 emu/g respectively and it is observed that Mr increases as the NFO content is increased. The saturated magnetization (Ms) values are 6.1435 emu/g, 8.16 emu/g and 12.1088 emu/g for xNiFe2O4 – (1-x) BaTiO3 where x=0.2, 0.3 and 0.4 respectively. Saturation magnetization (Ms) enhances remarkably with the increase in the ferrite content. The ferroelectric characteristics of the composite samples show an enhancement with the BTO increase in the composition. The polarization Pmax value for the composites 20:80, 30:70 and 40:60 are 6.41 μC/cm², 2.43 μC/cm² and 0.9493 μC/cm² respectively. Remnant polarization (Pr) values are 1.02 μC/cm², 0.42 μC/cm² and 0.19 μC/cm² for the composites (x=0.2, 0.3 and 0.4) respectively. The samples exhibit a very low leakage current density of the order of 10⁻⁸ A/cm². Average particle sizes of the composites are obtained as 88 nm, 68 nm and 94 nm by transmission electron micrograph.