Carbon nanofibers with various contents of Co nanoparticle were synthesized by a two step process of electrospinning and subsequent heat treatment. The thermal stability, phase composition, microstructure and electromagnetic characteristics of the carbon nanofibers were characterized by differential scanning calorimetry-thermogravimmetric analysis (DSC-TGA), X-ray diffraction(XRD), scanning electron microscope(SEM) and vector network analyzer(VNA), and the microwave absorption performance was studied.The results indicate that the crystallinity of composite nanofibers is moderate when the carbonization temperature is 800℃.The amorphous carbon is partially converted into graphite and CoAc2 completely reduces to face-centered cubic structured Co nanoparticle. The fiber is intact and beads-on-string structure exists in the fiber networks. The electromagnetic characteristics of the carbon nanofibers significantly improve by the doping of Co. The Carbon nanofibers containing 7%(mass fraction) as fillers with thickness of 1.5mm exhibit maximum effective absorption bandwidth of 4.5GHz, and it is obviously improved compared to pure carbon nanofibers.
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