Structural, dielectric, and magnetic properties of Cu-doped Ni-Zn ferrites

An effect of Cu-doped Ni-Zn nanoferrite particles synthesized through the citrate gel auto-combustion method on structural dielectric and magnetic properties was investigated. The structural characterization of synthesized powder is investigated using XRD (X-ray diffraction), FE-SEM (field emission scanning electron microscopy), EDXS (energy-dispersive X-ray spectroscopy), AFM (atomic force microscope), and TEM (transmission electron microscope). All prepared samples were established to have a single-phase spinel structure and fine grain size with an Fd-3 m space group. The lattice parameter, volume, and crystallite size decrease with increasing copper substitution. By adding copper ions, the surface area rises from 123.9 to 187.4 m² g⁻¹. The surface roughness is increased by AFM examination from 7.6 to 11 nm. From the AFM samples, it is shown that they are soft to hard in nature due to the Cu doping. The real imaginary impedance and the complex electric modulus were studied within the frequency range of 20 Hz to 1 kHz at room temperature, respectively. In the Cole–Cole plots studied for dielectric constant, it was observed that all samples had single semi-circles and continuously decreased with increasing copper content. This shows that the prepared material is good for high-resistance applications and the fabrication of multilayer inductor chips. The magnetic characteristics of hysteresis loops were studied at room temperature using a VSM (vibration sample magnetometer) for nanoferrites. The prepared ferrites samples were examined; copper doping increased the width of the loops, which confirms the change from soft to hard magnetic material. They are utilized in data processing, telecommunications, and the automobile industries. At low temperatures, the prepared samples showed superparamagnetic behavior. It is used in medical and electrical device applications.