Structural, optical and dielectric properties of nickel zinc spinel ferrites synthesized by co-precipitation method

We report the synthesis, structural, optical and dielectric properties of single-phase spinel of Ni-substituted Zn nanoparticles prepared by co-precipitation method. The annealed samples at 1000 °C were characterized by X-ray diffraction ( XRD ) technique, infrared spectrophotometer ( FTIR ), UV–VIS spectrophotometer and dielectric measurements. X-ray diffraction analysis shows that the increase of zinc content has been manifested on crystallite size and lattice parameter. Crystallite size and lattice parameter were systematically increased from 83 to 130 nm and 8.386 to 8.443 Å, for x varied from 0.5 to 0.9. The FTIR analysis show two absorption bands in the wave number range of 400–540 cm −1 . The UV–VIS analysis shows that the estimated optical energy band gaps (E g ) of the samples, through Tauc plots, do not exceed 5 eV which confirms the semiconductor nature of our samples. The dielectric behavior was investigated as function of both frequency (1 kHz–1 MHz) and temperature (298–700 K), and the electrical response was investigated by impedance spectroscopy measurements.