Structural, dielectric properties of functionalized MWCNTs with Ce³⁺ ion doped zinc spinel ferrite nanocomposites for technological applications

Structural and dielectric properties of a nanocomposite comprising multi-walled carbon nanotubes (MWCNTs) based on spinel ferrite were examined for high-frequency applications. To that end, ZnCe_0.2Fe_1.8O₄ (ZCF) spinel ferrite nanoparticles were synthesized via sol-gel auto-combustion. Subsequently, (ZCF)_1-x/(MWCNTs)_x nanocomposite (x = 0–25 wt.%) was prepared using dispersion-assisted ultrasonication. X-ray diffraction (XRD) results were recorded at room temperature and examined to determine the structural arrangement of the composite as well as to identify phases, measure the crystallite size, and calculate lattice parameters and structural defects. The results show that the MWCNTs were finely linked with the nanoparticles without compromising cubic structure. Transmission electron microscopy (TEM) analysis was performed to examine the precise morphology, agglomeration, particle size, interplanar spacing and diameter. The dielectric measurements of the samples were obtained in a wide range (1 MHz to 3 GHz) at room temperature. Dielectric parameters were analyzed, including the real and imaginary parts of permittivity (ԑʹ and ԑʹʹ), AC conductivity (σ_ac), and tangent loss (tanδ). Additionally, the real and imaginary parts of modulus (Mʹ and Mʹʹ) and Cole-Cole plots of the prepared samples were studied. The MWCNTs have positively affected the structural and dielectric properties of the host spinel ferrite nanoparticles. The observed significant variations suggest prepared nanocomposites are suitable for high-frequency energy storage applications.