Optimization of Magnetic Dielectric Nanocomposites Obtained by Facile and Low-Cost Fabrication for Effective Absorption of Electromagnetic Waves

Abstract

F Heydari, S S Seyyed Afghahi, A A Ebrahimi Valmoozi and Sayed Mohamed Bagher Bahrani

This work presents the synthesis of Fe3 O4 nanoparticles (FNPs) and nanocomposites (NCs) of FNPs and functionalized carbon nanotubes (CNTs) at varying weight ratios for application in 8–18 GHz electromagnetic waves (EMW) absorb- ers. Their dielectric, magnetic, and structural characteristics were also examined. To create the desired NCs, CNTs are first mixed with FNPs at various weight ratios. The magnetic properties of the samples were ascertained using a vibrat- ing sample magnetometer, and the dielectric properties of all the samples were examined by a vector network analyzer at room temperature after the crystal structure of the samples was determined by X-ray diffraction, surface morphol- ogy, and elemental analysis by scanning electron microscopy, energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. Fe3 O4 @CNTs NCs in six different weight ratios (NC1 -NC6 ) were prepared. Sample NC3 , with a thickness of 2.25 mm, exhibited the greatest loss in the X band, measuring -27.07 dB, out of all the samples. Addition- ally, the NC4 sample which has a thickness of 5.00 mm, had the best loss, which came in at -38.21 dB in the Ku band. A data-driven method developed for multi-parameter optimization was then used to find out the optimal ratio weight ratio and sample thickness based on the experimental data. Samples with minimum reflection loss -34.1 dB (-41.5 dB), and others with effective bandwidth coving 69.0 % (71.4 %) in the X band (Ku band) were obtained.

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