Wideband (8–18 GHz) microwave absorption dominated electromagnetic interference (EMI) shielding composite using copper aluminum ferrite and reduced graphene oxide in polymer matrix

The development of an efficient radar absorbing material (RAM) is a need of the day due to rapid growth in satellite, electronic, and telecommunication industries (especially, in the GHz frequency region). Herein, an easy fabrication technique is presented to design a lightweight and flexible absorption dominated electromagnetic interference shielding material by dispersion of magnetic nanoparticles of a CuAl₂Fe₁₀O₁₉ (CFA) decorated reduced graphene oxide (RGO) filler into the polyvinylidene fluoride (PVDF) matrix. This has been done by a simple chemical reduction method in the presence of hydrazine. It was observed that the synergetic effect of all filler contents along with multiple relaxation mechanisms due to the interface of RGO, CFA, and PVDF leads to strong absorption rather than reflection. This makes the composite an excellent candidate for RAM in the X band as well as in the Ku band. To develop a material for absorption in wideband frequencies is challenging, especially if the intended absorption is above 60 dB. In the present work, shielding efficiency (SE) of ∼60 dB in the X band and ∼50 dB in the Ku band has been achieved with more than 90% SE due to absorption. The effect of an individual filler content in wave attenuation has been analyzed from the point of view of absorption coefficient, complex permittivity and permeability, and attenuation constant.