核壳结构Fe-Fe_3C@C微波吸收材料的制备及性能研究

Preparation and Microwave Absorption of Core-shell Fe-Fe_3C@C Microwave Absorbing Material

采用水热法原位聚合Fe^(3+)/C_6H_(12)O_6结合高温碳化制备了Fe-Fe_3C@C复合微波吸收材料;通过X射线衍射、透射电子显微镜、矢量网络分析仪对样品的物相、微观形貌及吸波性能进行测试分析。结果表明,磁性颗粒Fe-Fe_3C被厚约10 nm的石墨碳包覆形成核壳结构,材料具有高的比表面积205.5m^2·g^(-1)与低的表观密度2.97 g·cm^(-3).其吸波性能优异,当涂层厚度为2.5 mm时,其最小反射损耗(RL)达到最低值-14.2 dB,主要归因于复合物有效的阻抗匹配特性及多重界面极化效应。Fe-Fe_3C@C复合材料优异的性能使其有望作为一种潜在的轻质微波吸收材料。

The core-shell Fe-Fe3C@ C composite was successfully prepared by the in-situ polymerization of Fe^3＋/C6H12O6 and the subsequent high-temperature carbonization. The phase composition,microstructure and microwave absorption of the as-prepared sample were measured through X-ray powder diffraction（ XRD）,Transmission Electron Microscopy（ TEM） and vector network analyzer. The results showed that the Fe-Fe3C particles were encapsulated by graphitized carbon layers（ ≈10 nm） to form the core-shell structure with high surface area of 205.5 m^2·g^-1 and low apparent density of 2.97 g·cm^-3. Fe-Fe3C@C composite exhibited excellent electromagnetic absorbability,a minimum reflection loss（ RL） of -14.2 dB was observed when the matching thicknesses reached 2.5 mm. This was originated mainly from the effective impedance match and multiple interfacial polarizations. Due to the outstanding microwave absorption,the core-shell Co3Fe7@C composite is a promising candidate for lightweight microwave absorption material.