单壁碳纳米管-CoFe_2O_4双层复合材料的微波吸收特性

Microwave absorption properties of single-walled carbon nanotubes-CoFe_2O_4 double-layer composites

通过直流电弧放电法制备了高结晶性单壁碳纳米管(SWCNTs),采用溶胶凝胶自燃法制备CoFe_2O_4,并将两种材料复合制成SWCNTs-CoFe_2O_4双层吸波材料。使用Raman光谱、XRD、SEM、TEM和矢量网络分析仪对SWCNTs和CoFe_2O_4的形貌、结构和电磁性能进行了表征,并利用传输线理论分析了SWCNTs-CoFe_2O_4双层吸波材料在2~18GHz频带内的微波吸收性能。结果表明,相对于单一材料,SWCNTs-CoFe_2O_4双层复合材料的吸波性能得到了极大提高。当CoFe_2O_4作为匹配层、SWCNTs作为吸收层时,通过调节匹配层和吸收层的厚度,SWCNTs-CoFe_2O_4双层复合材料的最强反射损耗可以达到-61.13dB,低于-10dB的吸收带宽达到7GHz(8~15GHz)。因此,SWCNTs-CoFe_2O_4双层复合材料是一种新型的有应用前景的高吸收宽频带吸波材料。

The high crystalline single-walled carbon nanotubes（SWCNTs）were prepared by direct current arc-discharge method and the CoFe2O4 nanoparticles were prepared by sol-gel method.The double-layer composites for microwave absorption were fabricated by compositing SWCNTs and CoFe2O4.Their phase structures,surface morphologies and electromagnetic parameters were characterized by Raman spectrum,XRD,SEM,TEM and vector network analyzer.The microwave absorption properties of SWCNTs-CoFe2O4 double-layer composites were calculated according to transmission line theory in the frequency range of 2-18 GHz.The results show that the absorption property of SWCNTs-CoFe2O4 double-layer composites is improved greatly.The best reflection loss of SWCNTs-CoFe2O4 double-layer composite reaches-61.13 dB as the match layer is CoFe2O4 and the absorbing layer is SWCNTs.The absorbing bandwidth with the reflection loss values below-10 dB of SWCNTs-CoFe2O4 double-layer composites is 7 GHz which from 8 GHz to 15 GHz.SWCNTs-CoFe2O4 nanoparticles double-layer composites could be described as an excellent absorbing material with high reflection loss and broad absorbing bandwidth.