Synthesis α-Fe₂O₃/SnO₂@PANI ternary composites for X-band electromagnetic wave absorption

α-Fe₂O₃/SnO₂@polyaniline composites were prepared by combining a hydrothermal reaction and an emulsion polymerization process. The sizes of α-Fe₂O₃ and SnO₂ particles dispersed into PANI were 80–120 and 8 nm, respectively. The structure, morphology, and electromagnetic (EM) parameters were characterized by using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and vector network analysis. To achieve the absorption of different EM bands, the EM wave absorption properties of α-Fe₂O₃/SnO₂@PANI composites with different stannic oxide content were investigated according to transmission line theory. Polarizations and multiple reflections in the composite absorber play a key role in EM wave absorption. The α-Fe₂O₃/SnO₂@PANI composites exhibited high EM absorption capacity and an optimal reflection loss of −50.3 dB at 9.9 GHz with thickness of 2.7 mm. Moreover, the composite could reach an effective absorption bandwidth (below −10 dB) from 7.84 to 12.08 GHz. Thus, the synthesized composites are suitable candidates for highly efficient EM wave absorption in the entire X-band.