Fabrication of hexagonal platelets of Fe₃O₄/Fe₂O₃/C modified with polyacrylamide for excellent electromagnetic wave absorption

In order to improve the weak dielectric loss capability and poor impedance matching of Fe₃O₄, the hexagonal plates of Fe₃O₄/Fe₂O₃/C nanocomposites were rationally constructed in this paper by utilizing electrostatic attraction and cross-linking, using polyacrylamide (PAM) as templating agent and viscosity modifier. The stacked hexagonal plates constructed a conductive network and utilized the structural properties of Fe₃O₄ to promote the transfer and jump of free electrons, which effectively improved the conduction loss. The heterogeneous interface was effectively constructed due to the presence of Fe₂O₃ and trace carbon, while the transfer and leap of free electrons promoted the generation of interfacial polarization, resulting in magnetoelectric coupling and effective improvement of polarization loss. The results show that the effective absorption broadband reaches 4.08 GHz when the matching thickness of the composite is 2 mm. A minimum reflection loss of −43.79 dB is realized at a matching thickness of 1 mm. The PAM modification proved to be an effective means to modulate the morphology and composition of the materials.