Sm2O3填充碳纳米管／磁性金属微粉双层吸波复合材料的制备与吸波性能

通过湿化学法制备了Sm2O3填充碳纳米管吸收剂，并依据传输线理论和阻抗匹配原则，设计制备了环氧树脂基Sin203填充碳纳米管／磁性金属微粉双层结构吸波复合材料．采用透射电镜、扫描电镜和X射线衍射分析对Sin2O3填充碳纳米管和磁性金属微粉的微观形貌和结构进行了分析，HP8722ES矢量网络分析仪测量了材料在2～18GHz频率范围内的吸波特性．研究表明：与未填充碳纳米管相比，Sm2O3填充碳纳米管的磁损耗正切增大，吸收频带变宽，同时吸收峰由C波段迁移到中频X波段．这种双层结构吸波复合材料具有较好的宽频带吸波效果，其匹配厚度为dm=5．0mm时，在2．8和14．2GHz处有两个吸收峰，反射率小于-10dB的频宽为0．98GHz，反射率低于-5dB的频宽达6．46GHz，在S波段均低于-5dB．

Preparation and microwave absorbing properties of rare-earth Sm2O3 filled carbon nanotubes/magnetic metal/epoxy double- layer absorbing composite

Rare-Earth Sm2O3filled carbon nanotubes were prepared by wet chemistry solution method. According to the transmission line theory and impedance matching principal, a kind of double-layer absorbing composite was prepared. The surface layer and last layer are composed of Sm2O3 filled multiwalled carbon nanotubes （Sm2O3-MWCNTs） and the magnetic metal powder, respectively. Sm2O3- MWCNTs and magnetic metal powder were characterized by TEM, SEM and XRD. The microwave absorbing properties of the composites were measured in the frequency range of 2-- 18 GHz. Compared with the unfilled MWCNTs, the absorbing peaks of Sm2O3-MWCNTs moves to the higher frequency and the absorbing bandwidth was widened. The results of experimental measurement show that the double-layer composite has good absorbing performance in low frequency region. There are two absorbing peaks in the frequency range of 2-18GHz with the matching thickness of 5.0 mm, correspondingly, the bandwidth below-10 dB and -5dB is 0.98 GHz and 6.46 GHz.