Synergistic Hollow Structure Design and Defect Engineering in Dandelion-Like α-MnO₂ for Superior Radar-Infrared...

Radar-infrared compatible materials have emerged as a pivotal research focus on developing next-generation multispectral stealth technologies. However, achieving high-performance compatible stealth in a single integrated coating remains a significant challenge. This study proposes the design of a unique ion-modulated α-MnO₂ with a dandelion-like hollow structure, which functions as a promising filler to achieve superior radar-infrared compatible stealth property in a single-layer coating using epoxy resin as the binder. The intriguing phenomenon is primarily attributed to the synergistic effects of multitiered hollowness and defects induced by low-valence cation doping, which enhance polarization loss behaviors and further reduce thermal conductivity. As a result, the remarkably broadband microwave absorption (RL←10 dB) of 8.9 GHz is achieved, covering most of X/Ku bands. Meanwhile, the thermal conductivity coefficient (λ) of the coating is prominently reduced from 0.59 to 0.31 W m^-1 K^-1, with actual thermal radiation signals being visually suppressed. Therefore, this work presents a significant solution to address the inherent microwave absorption incompatibility of conventional thermal insulation coatings, offering a new strategy in exploring advanced multispectral stealth materials.