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 α-Fe/C(a) and Fe₂B/C(a). The real and imaginary parts (ε_r′ and ε_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 (μ _r″) exhibited a wide peak in the 1-9 GHz range for a-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.