Carbon nanotubes filled with ferromagnetic metal nanowires (M-CNTs) were synthesized by using chlorine-contained benzene (e.g.trichlorobenzene) as precursor.The wall thicknesses of M-CNTs synthesized by trichlorobenzene are much thinner than those by precursor without Cl (e.g.benzene).As-synthesized thin-walled M-CNTs exhibit remarkably enhanced field electron emission performance with a low turn-on field of 0.3 V/μm and better field-emission stability.Microwave-absorption coatings were made by dispersing as-synthesized M-CNTs into epoxy resin matrix.It is found that the reflection losses in S-band (2-4 GHz),C-band (4-8 GHz) and X-band (8-12 GHz) are enhanced in the order of FeCoNi-CNTs < FeNi-CNTs< FeCo-CNTs.The areal density of as-prepared coatings is only 2.35 kg/m2 when the coating thickness is 2.0 mm.This demonstrates that M-CNTs are promising to be used as lightweight and wide-band microwave absorbers.
LV RuiTao1,KANG FeiYu1,GU JiaLin1,WANG KunLin2 & WU DeHai2 1 Laboratory of Advanced Materials,Department of Materials Science and Engineering,Tsinghua University,Beijing 100084,China
