Synthesis and Broadband Absorption of Fe-Based Nanoparticles in the K_u-Band

In this work, we propose a simple method to characterize the broadband absorption of different sizes of iron (Fe) nanoparticles. The absorption feature in the K_u-band (14–18 GHz) of paint/Fe nanocomposites with different Fe concentration is systematically investigated. The experiments confirm that the proposed samples can maintain a broadband absorption (with A > 60%) from 14.6 GHz to 18 GHz and from 15.2 GHz to 18 GHz for the as-milled Fe proportions of 5.0 g and 7.0 g, respectively, in a total thickness of only 2.0 mm. Furthermore, the absorption properties of the un-milled Fe nanoparticles samples are also characterized, which show lower absorption (A < 50%) than the as-milled nanoparticles. Our results contribute to the characterization of the next generation of wireless electronic devices based on thin layers of magnetic nanoparticles.