Improved microwave absorption properties of core-shell type Ni@SiC nanocomposites

SiC coated Ni nanocomposites were fabricated by a facile arc-discharge method. XRD, HRTEM and XPS technologies indicate that as-prepared Ni@SiC nanocomposites consist of the Ni nanoparticles core and shells composed of crystalline SiC together with a few C/SiOx. The Ni@SiC nanocomposites absorbent present excellent microwave absorption in C-Ku band. The strongest reflection loss (RL) of Ni@SiC-parrafin composites achieve -42.1 dB at 11.2 GHz with its absorption bandwidth below -10 dB covering the whole X band at a matching thickness of 2.88 mm. Moreover, the RL values of Ni@SiC nanocomposites absorbent below -10 dB are about 1.6-2.5 times of those of the Ni nanoparticles absorbent at absorbent thicknesses of 1.4-5.5 mm. Furthermore, the maximum absorption bandwidth exceeding -10 dB is about 7.2 (6.2-13.4 GHz) for Ni@SiC-paraffin composites at a relatively thin matching thickness of 3.0 mm, covering the almost half C band and the whole X band.