Facile and low-cost fabrication of Fe3O4@CNTs nanocomposites for effective absorption of electromagnetic waves with high efficiency

In this paper, Fe 3 O 4 nanoparticles (NPs) and nanocomposites of Fe 3 O 4 NPs and functionalized carbon nanotubes (CNTs) under different weight ratios have been made for use in electromagnetic waves (EMW) absorbers in the frequency range of 18-8GHz. Therefore, their structural, magnetic, and dielectric properties were investigated. At first, iron oxide NPs with the chemical formula Fe 3 O 4 were successfully synthesized by the nitrate-citrate method. Then ,CNTs are combined with Fe 3 O 4 NPs under different weight ratios until the desired nanocomposite is formed. After determining the crystal structure of the samples by X-ray diffraction (XRD), Surface morphology and elemental analysis by scanning electron microscope (FESEM) and energy dispersive spectrum attached to it (EDS), Fourier transform infrared spectroscopy (FT-IR), Determining the magnetic properties using a vibrating sample magnetometer (VSM), And checking the dielectric properties of all the samples were done by vector network analyzer (VNA) at room temperature. Fe 3 O 4 NPs /carbon nanotubes (Fe3O4/CNTs) nanocomposites were prepared in six different weight ratios and fully characterized. That among the examples, Sample NC 3 under thickness d = 2.25 mm had the best loss in the X frequency band, which came − 27.07 dB. Also, sample NC 4 under thickness d = 5.00 mm had the best loss in the Ku frequency band, which came − 38.21 dB.