Complex permittivity, permeability and electromagnetic wave absorption of α-Fe/C(amorphous) and Fe2B/C(amorphous) nanocomposites

The complex permittivity, permeability and electromagnetic (EM) wave absorption properties have been investigated for resin compacts containing 75 wt% composite powders of alpha-Fe/C(a) and Fe2B/C(a). The real and imaginary parts (epsilon(r)' and epsilon(r)) of relative permittivity for the resin composites remained almost constant in the 0.05-20.05 GHz range. The imaginary part of the relative permeability (mu(r)) exhibited a wide peak in the 1-9 GHz range for alpha-Fe/C(a) and in the 2-18 GHz range for Fe2B/C(a). Both resin composites exhibited good EM wave absorption properties (RL <-20 dB) in the 4.4-8.3 GHz range with an absorber thickness of 1.9-3.4 mm, and in the 7.5-16 GHz range for an absorber thickness of 1.2-2.2 mm, respectively.