Improved microwave absorption performance of modified SiC in the 2-18 GHz frequency range

Aiming to improve the microwave absorption performance of SiC, various methods including doping and changing the shape were adopted. In view of doping, B-doped silicon carbide (B-SiC) with a B content of 3 mass% was prepared via a simple carbothermal reduction method. By using different raw materials, SiC both in nanowire and powder forms was obtained. The microwave absorption performance was investigated. The results show that B-SiC nanowires exhibit a far more improved microwave absorption ability in the frequency range of 2-18 GHz compared with SiC nanowires. The effective absorption bandwidth of the reflection loss below -10 dB is 3.52 GHz, and the maximum reflection loss of -37.94 dB at 14 GHz with a thickness of 1.5 mm indicates that B-SiC nanowires could be used as an effective microwave absorbing material. The combination of the enhanced electrical conductivity caused by B doping and the network formed from nanowires contributes to the enhanced microwave absorption.