Microwave absorbing property of Fe-filled carbon nanotubes synthesized by a practical route

Fe-filled carbon nanotubes were prepared reliably and economically via pyrolyzing of ferrocene and activated carbon. The sample was characterized by high-resolution transmission electron microscopy, electron diffraction and fast Fourier transforms. The complex relative permittivity and permeability parameters were measured in a frequency range of 2–18 GHz and microwave absorbing behavior was investigated. The sample exhibits the maximum reflection loss and the widest bandwidth of below −5 dB is −11.29 dB and 4.13 GHz (matching thickness = 2.5 mm), respectively.