Broadband electromagnetic-wave absorption by FeCo/C nanocapsules

Electromagnetic-wave absorption by FeCo/C nanocapsules has been investigated. In contrast to earlier reported materials, including other nanocapsules, the absorption amplitude of FeCo/C nanocapsules is found not to decrease with increasing absorption-layer thickness. A reflection loss (RL) exceeding -20 dB can be obtained for all frequencies within the 2-18 GHz range by choosing an appropriate layer thickness between 1.6 and 8.5 mm. The broadest bandwidth (RL values exceeding -10 dB) from 10 to 18 GHz, covering half of the X-band and the whole K-u-band, is obtained for a 2 mm layer.