Study of structural, electromagnetic and dielectric properties of cadmium substituted Ni–Zn nanosized ferrites

Abstract

Sol-gel auto-combustion method was adopted to prepare Cd2+ ions substituted Ni–Zn nanosized ferrites having a chemical formula Ni0.5Zn0.5-xCdxFe2O4 (0.0 ≤x≤0.4). Their structural, electromagnetic, and dielectric properties were investigated by using XRD, FE-SEM, EDS, FTIR, VSM, and IS. The XRD analysis revealed a single-phase cubic structure of all samples. The addition of cadmium increased the lattice constant and cell volume of Ni–Zn ferrite due to the difference in the ionic radii between Cadmium (0.97 ​Å) and Zinc (0.74 ​Å). FESEM images showed irregularly shaped grain sizes in the range of 40 to 73 ​nm with random orientations and some agglomeration. The FTIR analysis also confirmed the presence of spinal ferrite phase functional groups in all samples. The saturation magnetization decreased (from 89.51 to 71.32 emu/g) with increasing cadmium content. However, the remanent magnetization and coercivity parameters increased with an increase in cadmium content. The dc resistivity as a function of the temperature of all samples was investigated, and the activation energies were found to be in the range of 0.48 to 0.51 ​eV. The dielectric loss decreased with increasing cadmium content. However, the dielectric constant and dielectric loss tangent (tan) varied non-monotonically with increased cadmium content.