Bifunctional ceramic material: Li doping enhances the electromagnetic wave absorption and infrared stealth performance of SnO2 ceramics

Abstract

Semiconductor oxides have been widely used in the fields of electromagnetic wave absorption and infrared stealth due to their easily adjustable dielectric properties. However, due to its low dielectric properties, pure SnO2 limits its further development in the field of multifunctional stealth materials. Research has shown that doping with metals or other elements can significantly improve the dielectric properties of SnO2, thereby enhancing its electromagnetic wave absorption effect and effectively reducing its infrared emissivity, thereby achieving better stealth performance. Li doped SnO2 ceramics were prepared by solid-state reaction method. The absorption performance of SnO2 in the 8.2–12.4 GHz band and the infrared emissivity characteristics in the 3–5 μm and 8–14 μm bands were studied by doping different masses of Li into SnO2. The system studied the influence of different Li doping contents on the microstructure, morphology, dielectric constant, and infrared emissivity of SnO2. When the Li doping content is 0.3 wt%, the RLmin of the prepared material is as low as −60.82 dB at a frequency of 9.3 GHz and a thickness of 2.91 mm. Its excellent electromagnetic wave absorption performance is mainly attributed to its good impedance matching and polarization effect. Meanwhile, the lowest emissivity values of the doped samples in the 3–5 μm and 8–14 μm infrared bands are 0.358 and 0.84, respectively. These results may provide more ideas for the subsequent semiconductor doping in the field of radar infrared compatible stealth materials.