Biomimetic Sea Urchin-like Nano-ferrite Structures for Microwave Absorption

Wideband absorption with low-frequency compatibility is always challenging for developing high-performance electromagnetic wave (EMW) absorbing materials. With magnetic loss and a sufficient polarization interface, ferrite materials are promising candidates for overcoming this challenge. To address impedance matching issues, a carrier material with a uniform pore distribution, namely, diatomite, is employed, resulting in a unique three-dimensional biomimetic structure. A biomimetic sea urchin-like nanomaterial composed of one-dimensional nanorod-shaped Fe3O4 (sea urchin-like nano-Fe3O4) is presented, demonstrating outstanding performance in EMW absorption. The optimized Fe3O4@FeP sample exhibits two absorption peaks spanning the C and Ku bands when the thickness is 5.35 mm. The experimental results show that the sea urchin-like nano-Fe3O4 achieves an astounding reflection loss of −60 dB at 6 GHz with a thickness of 3.9 mm and a maximum effective absorption bandwidth of 4 GHz at a thickness of 1.7 mm. This material design holds significant potential for low-frequency EMW absorption applications.