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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]

The polycrystalline sample of Bi(NiTiFe)O was synthesized using a standard high-temperature solid-state reaction technique. Room temperature structural analysis of the above material, carried out using X-ray diffraction data, shows the formation of a single-phase compound with orthorhombic structure which is different from that of its parent compound (BiFeO). The co-substitution of Ni and Ti at the Fe-site of BiFeO enhances its dielectric, ferroelectric and magnetic properties with significant reduction of electrical leakage current or tangent loss. Room temperature surface morphology and texture of the samples, recorded by a field-emission scanning electron microscope, reveal the uniform distribution of grains on the surfaces of the sample. Studies of dielectric, modulus and impedance spectroscopy on (Ni, Ti) modified BiFeO over a wide frequency (1 kHz-1 MHz) and temperature (25-500 °C) ranges provide many interesting features of the material useful for devices. Impedance and modulus plots were used as tools to analyze the sample behavior as a function of frequency. Cole-Cole plots showed a non-Debye relaxation. [ABSTRACT FROM AUTHOR]