Radar Absorbtion Performance in the K<sub>a</sub>- Band Region of Fe<sub>3</sub>O<sub>4</sub>/SWCNT/TiO<sub>2 </sub>Nanocomposite

This research has successfully synthesized Fe 3 O 4 /SWCNT/TiO 2 nanocomposite as a radar absorber for stealth technology applications in the Ka-band. The study aimed to investigate the nanocomposite's crystal structure, morphology, functional groups, magnetic properties, and radar absorption performance at a frequency Ka-Band range from 26.5 GHz to 40.0 GHz. The X-ray diffraction analysis revealed a crystalline phase of Fe 3 O 4 with a crystallite size of 14.26 nm and two crystalline phases of TiO 2 (anatase and rutile) with crystallite sizes of 5.12 nm and 27.51 nm, respectively. The scanning electron microscopy image showed SWCNT as a matrix with diameters of several nanometers and lengths of several micrometers, along with Fe 3 O 4 and TiO 2 particles as fillers with a particle size of 46.56 nm, consistent with the XRD characterization. Furthermore, the infra-red spectrum confirmed the presence of Fe 3 O 4 through octahedral and tetrahedral Fe-O bonds. C-O, C-C, and C=O indicated the presence of SWCNT. Meanwhile, -OH bonds also validated the success of their functionalization. Ti-O and Ti-O-C bonds stated the presence of TiO 2 bound to SWCNTs. The hysteresis curve exhibited superparamagnetic properties of the nanocomposite with a saturation magnetization of 9.38 emu/g. Furthermore, radar absorption measurement demonstrated that the nanocomposite absorbs radar with a maximum reflection loss of –1.51 dB at an effective frequency of 33.16 GHz, showing a potency for Fe 3 O 4 /SWCNT/TiO 2 nanocomposite as radar absorber in the Ka-Band Region, inspiring potential applications in stealth technology.