Development of a porous iron-based magnetic absorber with enhanced electromagnetic absorption performance

摘要

It is well known that the electromagnetic (EM) wave absorption performance is determined by nanostructure and material components. Based on this principle, this study reports a facile two-step method for synthesizing porous Fe/α-Fe_2O_3 nanoparticles with a tunable component ratio. The as-prepared hybrids, especially their pore size and phase composition, were characterized by X-ray diffraction (XRD), BET, and X-ray photoelectron spectroscopy (XPS). Furthermore, the EM wave performance was estimated by the coaxial line method, which revealed that a thin layer of nanoparticles (≤ 1.5 mm) exhibited good performance. The desirable bandwidth (reflection loss, RL ≤ - 10 dB) of 5.2 GHz was obtained when the thickness was 1.2 mm. The bandwidth was greater than 2.0 GHz when the thickness was 1.0 mm. The EM wave loss mechanism, especially the contribution of a porous structure, is discussed in depth. In addition, a suitable weight ratio is essential to balance impedance matching and attenuation ability.