Microwave absorption properties of a double-layer absorber based on nanocomposite BaFe 12 O 19 /α-Fe and nanocrystalline α-Fe microfibers

摘要: The nanocomposite BaFe12O19/α-Fe and nanocrystalline α-Fe microfibers with diameters of 1–5 μm, high aspect ratios large specific areas are prepared by the citrate gel transformation reduction process. show some exchange—coupling interactions largely arising from magnetization hard (BaFe12O19) soft (α-Fe) nanoparticles. For microwave absorptions, double-layer structures consisting each exhibit a wide band strong absorption behavior. When used as matching layer 2.3 mm in thickness an absorbing 1.2 thickness, optimal reflection loss (RL) achieves −47 dB at 15.6 GHz, bandwidth is about 12.7 GHz ranging 5.3 to 18 exceeding −20 dB, which covers 72.5% C-band (4.2–8.2 GHz) whole X-band (8.2–12.4 Ku-band (12.4–18 GHz). enhanced properties these absorbers mainly ascribed improvement impedance ability multi-reflection resulting dipolar polarization, interfacial interaction, small size effect.