Characterization and synthesis of Mn<inf>x</inf>Co<inf>(0.90−x)</inf>Ni<inf>0.10</inf>Fe<inf>2</inf>O<inf>4</inf> based flexible DNG metamaterial with EMI shielding and sensing application

Abstract

This article presents a sol–gel method based fabrication of DNG (Double negative) metamaterials using flexible microwave composites composed of MnxCo(0.90−x)Ni0.10Fe2O4. The sol–gel method is used to synthesize flexible composites with Mn25, Mn50, and Mn75 molecular compositions. XRD, FESEM, and coaxial probe-based dielectric assessment kits (DAK) are used to analyze the structural, morphological, and dielectric properties of synthesized flexible composites to justify their use as microwave dielectric substrates. DAK depicts the substrate dielectric constant as 6.63 and a loss tangent of 0.3254. The proposed flexible substrate performs better scattering parameters than FR4 and RO4533 materials and covers microwave frequencies S- and C-band. The measurement of the fabricated prototype verifies the simulated results of the flexible material (FM), and both results are in close concurrence. The transmission-blocking characteristics of the proposed FM make it a prospective candidate for Electromagnetic interference (EMI) shielding, which shows values of 40 dB, 40 dB, and 49 dB were observed at frequencies of 3.77 GHz, 4.68 GHz, and 5.50 GHz, respectively. Through the process of material characterization, the material selection, optimization, validation of sensor substances, coatings, and composition assure better sensitivity and dependability compared to reported articles. Therefore, the MnxCo(0.90−x)Ni0.10Fe2O4 composites-based flexible DNG metamaterials exhibit suitability for microwave technologies.