Carbon nanotubes filled with ferromagnetic alloy nanowires: Lightweight and wide-band microwave absorber

Abstract

Thin-walled carbon nanotubes (CNTs) filled with different ferromagnetic alloy (FeCo, FeNi, and FeCoNi) nanowires were prepared by using trichlorobenzene as carbon precursor. They were dispersed into epoxy resin and then coated onto 180×180 mm2 aluminum substrates to form microwave-absorption coatings with 2.0 mm thickness. Reflection loss exceeding −5 dB was obtained between 5 and 18 GHz for coating containing 1.3 wt % FeCo-filled CNTs. A minimum reflection loss value of −28.2 dB was achieved at 15.2 GHz in FeCoNi-filled CNTs/epoxy coating. The areal densities of coatings are only 2.35 kg/m2, which is favorable for the applications requiring low density.