Preparation and enhanced microwave absorption properties of Ni-Co attached single-walled carbon nanotubes and CoFe2O4 nanocomposites

The electromagnetism and microwave absorption properties were investigated in the frequency range of 2-18 GHz for the nanocomposites NiCo-SWCNTs/CoFe2O4 consisting of Ni-Co attached single-walled carbon nanotubes (NiCo-SWCNTs) and CoFe2O4 nanocrystals with different ingredient weight ratios. NiCo-SWCNTs were mass-produced by a direct current arc discharge in helium and CoFe2O4 was synthesized by a sol-gel method. Premium microwave absorption properties (mainly in K-u-band, i.e., 12-18 GHz) were obtained due to the appropriate combination of the complex permeability and permittivity resulting from the magnetic nanocrystals and high-crystalline NiCo-SWCNTs. The NiCo-SWCNTs/CoFe2O4 nanocomposites with 15 wt. % NiCo-SWCNTs exhibited the best microwave absorption property, whose reflection loss (RL) value reached -47.9 dB at 14.7 GHz and the absorption bandwidth (RL < -10 dB) was up to 7.1 GHz (from 10.5 to 17.6 GHz) with a matching thickness of only 1.8 mm. Our results indicate that the studied nanocomposite could be used as a promising candidate for lightweight microwave absorption materials. Published by AIP Publishing.