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This investigation involves the synthesis and study of dielectric, structural and impedance properties of polycrystalline Bi(Ni 2/5 Ti 2/5 Fe 1/5)O 3 (symbolized as BNTF) nano-ceramic. The BNTF polycrystalline sample was fabricated through the use of a conventional solid-state reaction route. X-ray structural examination reveals that the parent compound (i.e., BiFeO 3) crystallizes in the rhombohedral structure (space group-R3c) while that the BNTF compound crystallizes in orthorhombic symmetry. The substitution of NiTiO 3 into BiFeO 3 enhances various properties and reduces electrical leakage current. The average crystallite size is calculated to be 29 nm. The room temperature textures and surface morphologies of the specimen were verified by field-emission scanning electron microscope, and show uniform grains distribution on sample surfaces. Dielectric parameters (constant and tangent-loss) and impedance spectroscopy parameters of NiTiO 3 modified BiFeO 3 compound were investigated over a wide temperature range (25–500 °C) at different frequency (25 kHz-500 kHz), which offers several interesting features of BNTF material suitable for further device applications. [ABSTRACT FROM AUTHOR]

The Ni- and Ti-modified BiFeO3 nanoceramic (i.e., Bi(Ni0.45Ti0.45Fe0.10)O3) with various effective ball milling times (i.e., 10 h, 20 h and 30 h) were blended by planetary (high energy) ball milling method in conjunction with a traditional solid-state reaction route. The outcome of milling time on various properties, such as structural, electrical and ferroelectric features of Ni/Ti modified BiFeO3, was investigated thoroughly. These properties were interpreted using distinct characterization tools, such as powder X-ray diffraction, scanning electron microscope, transmission electron microscope, dielectrics and ferroelectric measurements. The particle size of as-synthesized compounds and the intensity of diffraction peaks decline obviously as the milling time rises due to the compression stress, shear friction and other mechanical forces, which are created inside ball mill jars. Investigation of dielectric properties (frequency dependent) displayed the boosted tendency of dielectric constant with increased co-doping concentration. Elaborated analysis of impedance data at selected sets of frequency/temperature estimates the grains influence and boundaries in the capacitive and resistive parameters of the synthesized samples. An elaborated investigation of the impedance spectroscopy spectrum evidently exhibited the size dependence impedance/dielectric relaxation features of the synthesized compounds. The frequency and/temperature dependence of conductivity (alternating current) confirmed the universal power law of Jonscher. The observed ferroelectric hysteresis loop trend reveals that the nanoceramic holds good ferroelectric properties. [ABSTRACT FROM AUTHOR]