Abstract:
The effects of magnesium, copper, and zinc substitutions on spinel ferrites have been investigated by the sol-gel technique. Ferrite compositions of Mg0.25𝑥Cu0.25𝑥Zn(1−0.5𝑥)Fe2O4 (where 𝑥 = 0.6, 0.7, 0.8 & 0.9) were prepared at a sintering temperature of 1100 ∘C with a presintering at 500 ∘C. X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-precision impedance analysis are used to characterize structural and dielectric properties, as well as the surface topography and morphology of the samples. A single phase, cubic spinel structure, with decreased lattice constant was observed. SEM micrographs revealed a homogeneous microstructure with uniform size distributions. Both the dielectric constant and dielectric loss tangent decrease, as the incident frequency increases up to a certain saturation point. The direct current (𝑑𝑐) resistivity profile shows that the resistivity increases with the temperature up to the Curie point, then it goes to a constant value. The quality factor (𝑄-factor) increases with the incident frequency. Hence, the high 𝑄-factor will make ferrites highly useful in applications, especially in multilayer chip inductors.
