Study of structural and electrical properties along with magnetic properties of Ni0.5−xMgxCu0.2Cd0.3Fe2O4 nanoferrites synthesized by employing sol–gel auto-combustion method

Abstract

The mixed ferrite sample Ni0.5−xMgxCu0.2Cd0.3Fe2O4 (0.0 ≤ x ≤ 0.5, in the steps 0.1) has been synthesized employing sol–gel auto-combustion process. From XRD diffractograms, it has been observed the simple cubic spinel structure of the ferrite samples. With the substitution of Mg ion, both the experimental and theoretical lattice constant increased. For x = 0.0, the value of experimental lattice constant has been found 8.459 A, which increases to a value 8.490 A for x = 0.5. The surface morphology has been studied by FESEM images. Besides, the chemical composition and the elemental distribution of the sample have been revealed by EDS study. From the vibration band, the formation of spinel ferrite has been confirmed from the FT-IR spectra. It is seen that the samples exhibit ferrimagnetic behavior at room temperature, which has been shown by the magnetic measurement done by VSM. Dielectric constant, dielectric loss tangent, ac conductivity, and impedance Spectroscopy have been analyzed within the range 20 Hz–15 MHz. In the lower frequency region, a typical dielectric dispersion based on Maxwell–Wagner type interfacial polarization has been observed. Dielectric loss tangent exhibits an analogous sort of behavior as that of dielectric constant. The grain and grain boundary effect on electric properties have been studied from the complex impedance analysis. It has been seen that both the grain resistance and grain boundary resistance increase with the substitution of Mg2+ content. A rise in ac conductivity has been observed with the increase in frequency.