New insight into the shape-controlled synthesis and microwave shielding properties of iron oxide covered with reduced graphene oxide

We proposed various approaches for the shape-controlled synthesis of iron oxide-RGO composites to evaluate the effect of different morphologies on their microwave shielding properties. The nature of various ferrite structures (flakes, cubes and rods) covered by reduced graphene oxide multilayers has been investigated using X-ray diffraction, Raman spectroscopy, FT-IR, scanning electron microscopy, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopic techniques. The electromagnetic interference (EMI) shielding effectiveness of iron oxide of different shapes coated with reduced graphene oxide was investigated in the Ku band frequency range (12.4-18 GHz). The rod shaped iron oxide covered with reduced graphene oxide sheets demonstrates the highest shielding effectiveness value of similar to 33.30 dB (>99.9% attenuation) as compared to flake and cube shaped iron oxides due to the combined effect of magnetic losses (hysteresis, eddy current loss and effective anisotropy) and dielectric losses (space charge polarization, interfacial polarization, surface defects, multiple scattering, etc.). These innovative proposed structures and their obtained EMI shielding results deliver a new insight into the morphology dependent nature of iron oxides covered with RGO nanosheets and create new opportunities for next generation EMI materials.