1成果简介
　　研究表明，多相战术对定制气凝胶材料的多光谱隐身性能至关重要。这得益于气凝胶基体与特殊附着物的巧妙组合。钡铁氧体（BaM）凭借可调谐磁性与卓越热调节能力成为多功能附着材料。本文，南京理工大学Yujing Zhang、徐锋教授等在《Chemical Engineering Journal》期刊发表名为“Synergy of resonance tailorable BaM and porous RGO aerogel for efficient microwave-infrared compatible stealth”的论文，研究首创性地将稀土（RE）改性BaM嵌入分级氧化石墨烯（RGO）气凝胶骨架，通过溶胶-凝胶法与自组装工艺实现精准调控。通过形成镧/钇改性BaM相（纳米尺度）与BaM@RGO框架（微米尺度），巧妙调和了复杂的微波损耗机制，同时实现了卓越的隔热性能。
　　实验表明，La/Y掺杂剂显著调控了BaM的磁晶各向异性，将自然共振频率移至X波段，填充后的复合气凝胶在仅2.2毫米厚度下实现7.7GHz的卓越有效吸收带宽（EAB）。此外，作为天然热绝缘体，BaM进一步提升了复合气凝胶的卓越红外隐身性能（隐身温度从136℃提升至~38.6℃）。这种兼具高效微波-红外兼容隐身特性的独特气凝胶，为设计适用于复杂电磁环境的多光谱功能材料开辟了新路径。
　　2图文导读 

　　图1. Systematic synthesis process of a) BaM (BFO/LBFO) powders, b) RGO/LRGO aerogels.

　　图2. (a-d) SEM characterizations. (e) XRD characterizations. (f-k) XPS spectra for Ba 3d, Fe 2p, O 1 s, La 3d, Y 3d and C 1 s orbitals of BFO, LBFO and LRGO samples. (l) Raman spectra of the RGO and LRGO.

　　图3. Morphology and crystallographic lattice structure characterizations of LBFO: (a-b) TEM images under varying magnifications and EDS mappings reflecting the elemental distributions. (c) High-resolution TEM image. (d-g) Detailed lattice fringes inside different grains as enclosed in (c) and the corresponding IFFT spectra. (h) TEM image illustrating the grain boundary as enclosed in (c). (i-k) Lattice diffraction spots, IFFT spectrum and fitted Exx-axis GPA strain maps derived from the boundary.

　　图4. (a-d) Electromagnetic parameters. (e-h) The 3D coutour maps of microwave reflection loss values. (i-l) EAB and RL distributions under the varying matching thicknesses.

　　图5. (a) Dielctric polarization behaviors of BFO/LBFO. (B) the as-caused 2D RL distributions derived from the polarization losses. (c-d) Magnetic natural resonance behaviors of BFO/LBFO and the corresponding RL distributions. (e-f) The permittvity and permeability shifts between RGO and LRGO samples. (g) The impedance mathcing conditions of RGO and LRGO.

　　图6. (a) Hysteresis loop cuves of obtained samples. (b) Concrete magnetic parameters derived from (a). (c) Eddy current coefficient curves. (d) Cole-cole circles and the corresponding dielectric loss constitutions. (e) Attenuation constants. (f) Schematic illustrations of microwave attenuation and absorption mechanisms.

　　图7. (a, b) Thermal infrared images illustrating the different surfaces of the RGO/LRGO aerogels touching the hot plate with a radiation temperature of ~136 °C for 20 s, 60 s, 120 s, 240 s and 600 s. (c-e) The relationship curves illustrating the upper surface temperature of the RGO/LRGO, temperature of the heating platform as well as the background environments. (f) Mechanisms explaining the thermal insulation processes in LRGO aerogel.
　　3小结
　　通过引入稀土掺杂剂并定制磁致晶体各向异性场，将BaM的磁共振频率精确移至X波段，使其成为2-18GHz频段探索混合RGO气凝胶的理想功能填料。由此，改性BaM封装的气凝胶展现出微妙平衡的介电常数，显著优化了阻抗匹配，丰富了微波损耗机制，并提升了热抑制效率。实现了覆盖X-Ku波段7.7GHz的超宽带电磁吸收，并具备卓越的热隔离性能。这项工作为基于稀土改性BaM与分级RGO气凝胶骨架的高效隐形材料开发奠定了基础。
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