A newly-designed magnetic/dielectric [Fe₃O₄/BaTiO₃@MWCNT] nanocomposite system for modern electromagnetic absorption applications

Highlights: • 80–93% absorption in the frequency range of 16.7–18 GHz is achieved absorption. • 80–90% absorption in frequency of 12.5–14.3 GHz by [email protected] composite. • Nanotubes play high attenuation electromagnetic waves role. - Abstract: Developments in electronic industries for telecommunications and demands for decreasing electromagnetic radiation pollution result in developing researches on microwave absorption materials. The target of the present study is to design materials with high absorption properties for electromagnetic waves in the 12–18 GHz range. Thus, Fe₃O₄ magnetic nanoparticles were syntheses through chemical co-precipitation reinforced by ultrasonic. Then, BaTiO₃ nanocrystalline powder was synthesized by the hydrothermal sol-gel method under atmospheric oxygen. Next, nano-particles of barium titanate were deposited on the multi-walled carbon nanotubes (BaTiO₃@CNT). It was concluded that a magnetic-dielectric nanocomposite has superior microwave absorption properties in comparison to individual magnetic or dielectric absorbers. Also, in order to obtain an optimum absorption in a wide frequency band, dielectric-CNT nanocomposites represents higher properties than magnetic-CNT composites. It is concluded that composites with more magnetic percentage showed better absorption in low frequency band (12 GHz), whereas composites with more dielectric percentage exhibited superior absorption for high frequency band (18 GHz). 80–93% absorption was obtained in the frequency range of 16.7–18 GHz by composite 40M.20F.40C (40% paraffin, 20% magnetite, 40% multi-walled carbon nanotubes). Also, composite [email protected] (40% paraffin, 20% barium titanate, 40% barium titanate deposited on multi-walled carbon nanotubes) showed the absorption of 80–90%.