Binary nickel ferrite/carbon hybrid nanofibers for multiband, strong electromagnetic wave absorption

It is anticipated that the advancement of efficient wave-absorbing materials across diverse frequency bands can meet the demands of covert communication and reduced radar detection, in particular, in the context of active camouflage in the era of electronic information warfare. In this study, a carbon-modified nickel ferrite (NiFe2O4) hybrid fiber was successfully synthesized via electrostatic spinning and in-situ carbothermal reduction. The carbothermal reduction temperature can be used to adjust the carbon content of NiFe2O4/C hybrid nanofiber, thereby enabling the tuning of the conductance loss. Furthermore, the effective wave-absorption frequency range can be finely adjusted from the Ku-band to the C-band. This is attributed to a deliberate tailoring, which enables the achievement of synergistic and complementary effects of the magnetic and dielectric properties, influencing the impedance matching level of each NiFe2O4/C hybrid absorber. A large electromagnetic loss indicates a high-efficiency energy conversion, and thus, the excellent microwave absorption properties indicate that this material exhibits promising potential for integration into multifunctional micro–nano electromagnetic devices and weaponry.