Hierarchically Confined LaFeO3/La2O3/Fe/CNF Nanocomposites Enabling Broadband Microwave Absorption, Thermal Management, and Laser Camouflage

The precise regulatory mechanism of multi-level confinement coordination remains unclear, and the structure-property relationships among component size, phase evolution, and material multifunctionality are still ambiguous, hindering the integrated optimization of wideband microwave absorption, laser camouflage, and thermal management. In this work, LaFeO3/La2O3/Fe/CNF nanocomposites (LFOCNFs) were prepared using electrospinning combined with high-temperature carbonization, establishing a multiple confinement system that encompasses ion confinement, pore channel confinement, and core-shell confinement. By regulating the lanthanum-iron ratio, PMMA template pore formation, and coaxial electrospinning process, precise control over material phase composition, grain size, and heterogeneous interface distribution was achieved. Test results revealed that PCNFs exhibited a minimum reflection loss (RLmin) of -55.83 dB at a thickness of 2 mm, with an effective absorption bandwidth (EAB) of 8.03 GHz (9.74-17.77 GHz) at a thickness of 2.6 mm. HCNFs, on the other hand, exhibited an RLmin as low as -62.68 dB at a thickness of 5.6 mm and achieved dual-band microwave absorption at 6.54 GHz within a 6.4 mm thickness (3.56-6.23 and 14.11-17.97 GHz). Multiple confinement structures can synergistically enhance magnetic-dielectric loss, multiple scattering in pores, and interfacial polarization effects, optimizing material impedance matching and electromagnetic wave attenuation. At 1.06 and 1.54 μm laser wavelengths, the reflectivity of LFOCNFs decreases to 7.62% and 7.73%, respectively, while exhibiting an ultra-low thermal conductivity of 0.0721 W/(m·K) and radiative heat dissipation characteristics. This work achieves integrated enhancement of multispectral camouflage, electromagnetic shielding, and thermal management capabilities, offering a straightforward preparation strategy for multifunctional stealth materials.