The microwave absorbing properties of CoFe2 attached single walled carbon nanotube/BaFe12O19 nanocomposites

Abstract

The CoFe2 attached single-walled carbon nanotubes (CoFe2@SWCNTs) and BaFe12O19 ferrite nanocomposites with different CoFe2@SWCNTs weight ratios (1, 3, 5, 7 wt%) were synthesized by a simple combination process. Then, the electromagnetic and microwave absorption properties were systematically investigated by a vector network analyzer in the frequency range of 2–18 GHz. High-quality CoFe2@SWCNTs were prepared by a direct current arc discharge method in one-step. BaFe12O19 nanocrystals were synthesized by a nitrate citric acid sol–gel auto-ignition method. The CoFe2@SWCNT/BaFe12O19 nanocomposites exhibited an efficient reflection loss (RL) and a wide absorption bandwidth. The minimum RL of −54.13 dB was observed at 11.84 GHz for the nanocomposite (5 wt% CoFe2@SWCNTs) with a thickness of 2.8 mm, 3.4 times greater than those without CoFe2@SWCNTs, and a broad absorption bandwidth of 4.64 GHz (<−10 dB) was achieved. In addition, the nanocomposite (1 wt% CoFe2@SWCNTs) shows a broader effective microwave absorption bandwidth of 7.12 GHz with a thickness of 1.9 mm. The experimental results reveal that the absorbing properties of the nanocomposites are greatly improved by controlling the CoFe2@SWCNTs weight ratio and the matching thickness of the absorber. This CoFe2@SWCNT/BaFe12O19 nanocomposite is anticipated to be applied in advanced microwave absorbers.