Electromagnetic wave absorption properties of porous carbon/Co nanocomposites

Porous carbon/Co nanocomposites were fabricated by a sol-gel method. The electromagnetic parameters were measured in the 2-18 GHz range. Compared with porous carbon composite, porous carbon/Co nanocomposite has larger dielectric loss due to the enhanced interfacial polarization relaxation loss and Ohmic loss. The maximum reflection loss of the porous C(Co) nanocomposite can reach 40 dB at 4.2 GHz with 5 mm in thickness and the primary microwave absorptive mechanism is ascribed to the dielectric loss. The effect of porous structure on microwave absorption property of the carbon/Co nanocomposite was also discussed. (C) 2008 American Institute of Physics.