Enhanced Microwave Absorption Properties of Urchin-like Fe/α-Fe2O3 Composite Synthesized by a Simple Thermal Oxidation

The urchin-like structure of Fe/α-Fe2O3 composite has been prepared by a simple thermal oxidation method. The obtained products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The microwave absorption property of the Fe/α-Fe2O3 composite was measured by vector network analysis (VNA). The excellent microwave absorption property of Fe/α-Fe2O3 composite was achieved due to the relatively low permittivity and unique isotropic antenna-like morphology. When the matching thickness is 2.5 mm, the optimal reflection loss of Fe/α-Fe2O3 reaches about −41.2 dB at 5.2 GHz. A possible mechanism of the improved microwave absorption properties of the composites was discussed.