Investigation of Transition Metal Ions Cu2+ and Mg2+ Doped Zinc Aluminate (ZnAl2O4) and Their Structural, Spectral, Optical, and Dielectric Study for High-Frequency Applications

Zinc Aluminate is an excellent dielectric material suitable for a variety of technological applications due to its high-quality factor, low dielectric loss, and appreciable conductivity. Here in this study, the preparation of Zn1−xMxAl2O4 (M = Cu2+, Mg2+: x = 0, 0.10) powders were carried out using the citrate-based combustion route. The structural, spectral, optical, stoichiometry composition, and dielectric performance of the synthesized nanoparticles were evaluated to explore the substitution effect of Cu2+ and Mg2+ ions. It was confirmed from XRD results that all the samples exhibited a monophase spinel structure. The estimated average crystallite size is calculated to be 23 nm. The functional group identification of the samples was monitored by FTIR spectroscopy. Scanning electron microscope (SEM) coupled with energy-dispersive X-ray spectroscopy analysis (EDAX) was utilized to confirm the composition of the samples. UV–Visible absorption spectroscopy demonstrated decrement in the band gap due to doping. Impedance spectroscopy displayed improved dielectric properties for the doped samples. The Cole–Cole plots enlightened the relaxation processes and provided information about the complex electrical behavior of the material. It was established that non-Debye relaxation was found to be prominent in the investigated aluminates. From the electrical parameters obtained, it displays the semiconducting nature of the zinc aluminate particles, and it can be utilized for high-frequency applications such as ceramic capacitors, resonators, and filters in high-frequency electronics. Overall, Zinc Aluminate is a versatile material with potential application in various fields of science and electronics.