Tailoring of electrical properties in nanostructured (NiO)_0.25(Fe₂O₃)_0.75 composite and compound for sensing applications

Abstract

Compound and composite of the (NiO) 0.25 (Fe 2 O 3 ) 0.75 nanoparticles have been prepared by without water and surfactants (WOWS), Sol-gel method. Synthesized nanoparticles are calcined at 500°C/2 h and pellets are sintered at 550°C/1 h. The compound and composite showed cubic lattice and rhombohedral crystallographic lattices respectively. Morphological analysis is done by Scanning electron microscope and Transmission electron microscope. UV characterization was done to calculate band gap energies for both samples. DC electrical conductivity as a function temperature from 373.15 to 703.15 K was done by two-probe method. DC conductivity has been explained by hopping mechanism. Activation energies were calculated from Arrhenius plots. AC electrical properties namely; dielectric constant, dielectric loss tangent, ac conductivity and impedance were measured as a function of frequency (20 Hz-3 MHz). AC electrical properties were explained by Maxwell-Wegner model, Koop's theory and Johnsher's power law. Composite of (NiO) 0.25 (Fe 2 O 3 ) 0.75 showed enhanced properties as compared to compound.

Synthesis and identification of structural, optical, electrical, and magnetic properties of novel ZnFe2O4/NiO nanocomposites

“…However, many factors affect the bandgap for example the structural considerations, the existence of impurities, and surface and interface effects [49]. Herein, the supplemental sub-bandgap energy levels, triggered by the interface and surface defects due to the introduction of NiO in ZnFe 2 O 4 /NiO NCs, could be the reason for the red-shift of the bandgap [50]. Similar behavior was reported before where the combination between ZnFe 2 O 4 and ZrO 2 nanoparticles leads to the formation of mixed metal oxide nanocomposite with reduced bandgap energy [51].…”

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Novel nanocomposites (NCs) of (100-x) ZnFe 2 O 4 /x NiO (x=0,10,20,30,40,50, and 100 wt. %) NCs have been successfully synthesized by the two-step co-precipitation method.

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