Carbon–Ni 6 Co 3 Fe 1 alloy hybrid foil for electromagnetic wave interference shielding in X-band and extremely low frequencies

Carbon-based materials, such as graphite foil, are widely recognized as excellent electromagnetic interference shielding materials due to their outstanding electrical conductivity, lightweight nature, and chemical inertness. While these materials serve as effective shields at high frequencies, their shielding performance for electromagnetic waves in the extremely low frequency regime is significantly diminished. In this manuscript, we propose an approach to fabricate carbon-based shielding materials that can be applied over the multiple electromagnetic spectral regions. By electrochemically depositing nickel, cobalt, and iron (NiCoFe) alloy film onto a graphite foil, we achieved a shielding composite covering extremely low and X-band frequencies. The nanostructured NiCoFe alloy film with excellent electrical and magnetic properties enhanced shielding effectiveness in the high-frequency regime by reflection and absorption, whereas extremely-low-frequency magnetic fields were effectively shielded through magnetic flux-shunting mechanisms. The enhanced shielding performance of the NiCoFe/graphite foil was also accompanied by improved thermal and mechanical properties. As our process is facile and scalable, we anticipate that this composite shielding strategy will potentially serve as a promising solution for practical electromagnetic interference shielding applications.