基于核壳结构Co3Fe7@C的高效微波吸收材料

Core-Shell Co3Fe7@C Composite as Efficient Microwave Absorbent

To reduce the density of the absorbent Co₃Fe₇, a core-shell Co₃Fe₇@C microwave absorbent was synthesized by preparing an iron/cobalt-containing carbon precursor followed by high-temperature carbonization. According to the X-ray diffraction (XRD) and transmission electron microscopy (TEM) results, Co₃Fe₇ particles were coated with graphitized carbon layers to form a core-shell structure. Furthermore, the Co₃Fe₇@C composite with a surface area and density of 358.5 m²·g^-1 and 2.25 g·cm^-3, respectively, exhibited excellent microwave absorbability. A minimum reflection loss (RL) of -43.5 dB and an effective bandwidth (RL below -10 dB) of 4.1 GHz were obtained at the coating thickness of 2 mm, which could be mainly attributed to the effective impedance match and multiple interfacial polarizations. Owing to the low density and remarkable microwave absorption, we believe that the Co₃Fe₇@C composite can be a promising candidate for use as a lightweight and efficient microwave absorbent.