Lightweight Porous Nico-Sic Aerogel with Synergistically Dielectric and Magnetic Losses to Enhance Electromagnetic Wave Absorption Performance

Abstract

Electromagnetic (EM) wave absorber with synergistically dielectric and magnetic losses is of great significance to enhance microwave absorption performance. In this paper, eggplant as raw material was used to obtain silicon carbide (SiC) aerogel through carbonization and subsequent carbothermic reduction, and then magnetic NiCo decorated SiC aerogel (NiCo-SiC) with a three-dimensional porous structure was prepared by a chemical plating method. The NiCo-SiC aerogel with a density of only 0.194 g/cm 3 mainly consists of porous SiC skeleton, SiC nanowires, and their surface distributed magnetic NiCo alloy nanoparticles. Moreover, the introduction of magnetic NiCo alloy nanoparticles not only provides additional magnetic loss but also promotes dielectric loss due to the formed heterogeneous interface . As a result, the obtained NiCo-SiC aerogel shows a minimum reflection loss ( RL min ) of −44.5 dB and effective absorbing bandwidth ( RL <−10 dB) of 7.6 GHz at a thickness of 3 mm. These dates show that the NiCo-SiC aerogel has an underlying application in lightweight and excellent EM wave absorbing material.

Keywords: NiCo alloy, SiC aerogel, Dielectric loss, Magnetic loss, Electromagnetic wave absorption