Magnetic properties and microwave absorption properties of carbon fibers coated by Fe3O4 nanoparticles

Fe3O4 nanoparticles were plated on carbon fibers from nitrate and dimethylamine borane solution at 90 °C for 1 h. The structures and morphologies of the composite were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The thickness of the Fe3O4 films is about 1 μm. The saturation magnetization of the Fe3O4/CFs composites reaches 39.5 emu/g and coercivity reaches 166.9 Oe. The reflectivity of Fe3O4 nanoparticles covered carbon fiber (2.90–5.12 mm in thickness) is less than −10 dB over the range of 3.52–10.01 GHz and −20 dB over the range of 5.49–7.75 GHz. The lowest reflectivity of the Fe3O4/CFs composites is −35 dB at 6.37 GHz for a layer of 4.41 mm in thickness.