Microwave absorption, physicochemical, elemental mapping, and high-frequency perspectives of the Co, Cu, Zn doped Ni-Ce absorbers for Ku band frequency

Abstract

The excellent absorbing ability, low weight, and thin size are the key challenges for addressing the electromagnetic issues in military systems and stealth missile technology. Recently, we increased the absorption features of the Co, Cu, and Zn-doped Ni spinel ferrites to improve the absorption performance of the absorbers in a high-frequency regime. The two-step process was employed to synthesize Co, Cu, and Zn substituted Ni-Ce nano ferrites with a nominal composition of Ni0.5x0.3Ce0.2Fe2O4 (X = Co, Cu, Zn). Various tools for the characterizations, such as XRD, FESEM, FTIR, TG/DTA, XPS, VSM, and VNA, investigated these synthesized nanocrystalline ferrites from structural, spectral, thermal, morphological, elemental, magnetic, dielectric, and absorption points of view. XRD results revealed the existence of cubic phase structure in Ni-Ce ferrites. The crystallite size was enhanced from 43 to 54 nm. FTIR spectra showed the existence of tetrahedral and octahedral bands of the Co, Cu, and Zn doped circular-shaped Ni-Ce ferrites. FESEM images revealed the mixed particles of polygonal, circular shaped Co, Cu and Zn doped Ni-Ce ferrite sample. Electron mapping analysis reveals the presence of Ni, Ce, Co, Zn, Cu, Fe, and O elements. VSM analysis was used to calculate the magnetization and other parameters of the samples. Co-doped NiCe absorber depicted RL of -46.8 dB for 2.9 mm thickness at 16 GHz, whereas the Cu-doped NiCe absorber depicted RL of -43.5 dB for 2.8 mm at 14.9 GHz. In addition, Zn doped NiCe absorber shows RL of -51.5 dB is perceived for 2.8 mm thickness at 17.6 GHz, respectively. The Zn-doped NiCe absorber is an excellent absorber for Ku band absorption applications. The prepared absorbers could be used for EMI shielding materials in the next-generation absorbing devices for multipurpose applications.