Low Temperature Solution Synthesis and Microwave Absorption Properties of Multiwalled Carbon Nanotubes/Fe3O4 Composites

Multiwalled carbon nanotubes (MWCNTs)/Fe3O4 nanocomposites were synthesized via a simple low temperature solution method. The phase structures and morphologies of the composite were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the Fe3O4 spheres of about 150 nm were linked with MWCNTs. The microwave absorption properties of the MWCNTs/Fe3O4 nanocomposites were measured by vector network analysis (VNA). A wide region of microwave absorption was achieved due to dual magnetic and dielectric losses. When the matching thickness is 2 mm, the reflection loss (RL) of the sample exceeding −10 dB was obtained at the frequency range of 9.9–12.4 GHz, with an optimal RL of −29.8 dB at 11.04 GHz. A possible mechanism of the improved microwave absorption properties of the composites was discussed.