Frequency dispersion of complex permeability and permittivity on iron-based nanocomposites derived from rare earth-iron intermetallic compounds

Abstract

Complex permittivity, permeability, and electromagnetic wave absorption properties of resin compacts containing 80 wt% composite powders of α-Fe/Y 2O 3 and ɛ-Fe 3N/Y 2O 3 were characterized by a conventional reflection/transmission technique. The real and imaginary parts ( ε ′ r and ε ″ r ) of relative permittivity for these resin compacts almost kept low constant between 0.5 and 10 GHz. The imaginary part ( μ ″ r ) of relative permeability exhibited a peak in the 1–5 GHz range on the α-Fe/Y 2O 3 resin composites, while “twin peak” dispersion in the 0.5–5 GHz range on the ɛ-Fe 3N/Y 2O 3 ones. The resin composites of α-Fe/Y 2O 3 and ɛ-Fe 3N/Y 2O 3 powders with thicknesses of 3.0–5.0 and 3.3–19.3 mm provided good electromagnetic wave absorption performances (reflection loss <−20 dB) in ranges of 2.0–3.5 and 0.6–4.4 GHz, respectively.