Investigating X-band shielding properties of hierarchical Ni-Zn alloy and Fe3O4/epoxy coatings on carbon fiber fabrics.

The increasing use of electronic devices has led to an increase in electromagnetic interference (EMI) pollution, which not only adversely affects the performance of electronic devices, but also poses potential risks to human health. Traditional EMI shielding methods work by reflecting incoming electromagnetic waves, but this approach can cause secondary EMI pollution. Absorption-based shielding effectively absorbs incoming EMI and offers an environmentally friendly solution. Since bare carbon-based materials exhibit minimal magnetic losses and limited microwave absorption capabilities, in contrast to higher electrical losses, we, in this study, focused on functional coatings on carbon materials and modification of dielectric and magnetic materials and designed hierarchical Ni-Zn alloy and Fe₃O₄/epoxy on carbon fiber fabrics (CFF). The X-band (8–12 GHz) electromagnetic interference (EMI) shielding properties and microwave properties of this design were investigated. The structural integrity and elemental composition of the design were verified using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM). Electromagnetic evaluation performed with a vector network analyzer (VNA) showed that, in particular, the CFF/Ni-Zn/Fe₃O₄-epoxy composite (CFF/NZ/F50E50) with a weight ratio of 50:50 exhibited the strongest reflection coefficient performance, reaching up to − 31.96 dB at 8.73 GHz. This sample also exhibited a wide reflection loss range exceeding − 20 dB from 8.41 to 9.08 GHz. The study revealed that the incorporation of Fe₃O₄ nanoparticles significantly improved the dielectric and magnetic loss properties of the composite coatings. The CFF/Ni-Zn/Fe₃O₄-epoxy composites exhibited a remarkable absorption contribution with an average of 43 dB. The SE_A value of CFF/NZ/F50E50 sample reaches 45.75 dB at 8.24 GHz and constitutes 99% of SE_T. The results showed that CFF/Ni-Zn/Fe₃O₄-epoxy composites are low-reflection and absorption-dominant EMI shielding materials. CFF/Ni-Zn/Fe₃O₄-epoxy has the potential to find applications in technological areas. [ABSTRACT FROM AUTHOR]