Abstract
A series containing five samples of nickel substituted copper spinel ferrite (NixCu1-xFe2O4) nanoparticles with five different nickel concentrations varying as x = 0.00, 0.03, 0.06, 0.09, 0.12, fabricated with the aid of sol-gel auto-combustion technique. Through X-ray diffraction analysis, the structural properties of the compound were determined, which revealed that the prepared nanomaterials possess a spinel nature which was confirmed due to the existence of a secondary phase. The crystallite size was ascertained by applying the Scherrer formula, which was brought up in the range of 8–11 nm. The experimental parameters such as magnetic stirring speed, the molarity of reactants, synthesis temperature, the quantity of citric acid, and annealing were kept controlled. The substitution of nickel in copper spinel ferrite made a significant effect on the structural variables such as crystallite size stacking fault, lattice strain, micro-strain, dislocation density, bulk density, Impedance Analyzer (LCR meter) was used to get the dielectric properties in the frequency extended from 1 Hz to 20 MHz. From the obtained results it was depicted that the synthesized nanomaterials might be able to give response to the electromagnetic radiations, hence these can be usefully applied in microwave devices. Tangent loss and dielectric constant are varied due to Ni2+ content. Impedance loss shows the grain boundaries are dominant as a function of Ni2+ content. Inverse relation of AC frequency with the dielectric constant exposed the existence of Maxwell–Wagner type interfacial polarization. The various dielectric plots give awareness about the conducting grains and resistive grain boundaries that play a vital role in understanding the dielectric relaxation in the material. The ac conductivity is also determined due to Ni2+ content. From the observed electrical parameters, it can be propounded that the prepared nanocrystalline particles hold semiconducting nature and can be employed as a dielectric in low-frequency devices, and might be utilized as a conductor in high-frequency devices.
•Nickel substituted copper spinel ferrites nanoparticles were successfully synthesized by sol–gel auto-combustion method.•The effect of Nickel doping in copper ferrites, on structural and electrical properties were investigated.•The structural parameters such as lattice constant, crystallite size, lattice strain, micro-strain were determined.•Frequency dependent dielectric, impedance and electric modulus properties are investigated in microwave region.•Ac conductivity in microwave region is also investigated.