Microwave absorption properties of MWCNT-SiC composites synthesized via a low temperature induced reaction

Abstract

The composites containing SiC and multiwalled carbon nanotubes (MWCNTs) were synthesized via the reaction of Si powders and MWCNTs induced by that of Na and sulfur. The MWCNT-SiC composites prepared at 600 °C exhibit excellent microwave absorbing properties, which reach a minimum reflection loss of -38.7 dB at a frequency around 12.9 GHz. The absorbing properties are bound up with the high yield of porous SiC spheres comprised of nanocrystals. The porous structure, high density of stacking faults in SiC crystallites, interfaces between MWCNTs and SiC spheres, grain boundaries between SiC nanocrystals, as well as the interfacial polarizations aroused therefrom, are responsible for the excellent microwave absorbing properties.