Structural, electrical and magnetic characteristics of Ni/Ti modified BiFeO₃ lead free multiferroic material

Recently, scientists and researcher are focussing on multiferroic materials which are widely used in various multifunctional devices. In this communication, synthesis and characterisation of nickel and titanium modified bismuth ferrite have been reported. A lead-free multiferroic compound, Bi(Ni_0.40Ti_0.40Fe_0.20)O₃, has been synthesized using solvent-free solid-state reaction route at 1073 K in an air atmosphere. The formation of a single-phase with orthorhombic symmetry and the substitution/concentration of Ni/Ti at the Fe-site of BiFeO₃ were confirmed by X-ray diffraction and energy dispersive X-ray microanalysis spectroscopy techniques respectively. Based on X-ray reflection profiles, the average particle size was estimated to be around 30 nm. Study of surface morphology of the compound by field emission scanning electron microscope has shown nearly uniform distribution of grains of different dimension with some voids. The density (measured by Archimedes method) of as-synthesized pellets was found to be nearly 92.8% of the theoretical density. A significant effect of substitution of multiple elements at the Fe site on dielectric constant and tangent loss of BiFeO₃ has been observed. Detailed analysis of dielectric and impedance data, collected in a wide range of frequency (1–1000 kHz) and temperature (298–773 K), has provided many important results on structure-properties relationship and dielectric relaxation of modified bismuth ferrite. Magnetic field dependent magnetisation, measured by vibrating sample magnetometer (VSM at room temperature), shows a significant enhancement in the value of remnant magnetization of Ni/Ti modified bismuth ferrite.