Nitrogen content dependent microwave absorption property of nitrogen-doped SiC materials annealed in N2: Opposing trends for microparticles and nanowires

摘要: Abstract Nitrogen-doped SiC microparticles (SiCp) and nanowries (SiCNWs) with different nitrogen contents were successfully synthesized by a simple effective method, in which SiCp SiCNWs directly annealed N2 at 1500 °C holding times to adjust the of for first time. The content N-doped increased time, from 2.91 at.% 3.05 at.% 1 h 5.05 at.% 5.25 at.% 4 h. size was larger than that pristine SiCNWs, while tended increase firstly then decrease. results dielectric parameters showed both real part e′ imaginary e″ permittivity samples greatly increasing N most frequency range, two opposing trends dependent microwave absorption property observed. electromagnetic (EM) wave capability significantly improved compared fully permeable SiCp, minimum reflection loss (RLm) maximum bandwidth (EAB) could be up to −33.5 dB 4.4 GHz, respectively. EM performance exhibited decreasing tendency content, RLm decreased from −57 dB to −51.2 dB N, to −29.3 dB N. Moreover, if experimental process present study decomposed into heat-treatment N-doping, played extremely negative effect on samples, N-doping still had positive impact performance. It is believed current work will provide new insight fabrication materials fascinating properties doping.