Dielectric properties of porous SiC/Si3N4 ceramics by polysilazane immersion-pyrolysis

Publication date: Available online 20 April 2019Source: Progress in Natural Science: Materials InternationalAuthor(s): Xiao Lin, Hongyu Gong, Yujun Zhang, Jianqiang Bi, Yurun Feng, Yu Liu, Shan WangAbstractThe SiC nanotubes were synthesized on porous Si3N4 matrix by polysilazane immersion-pyrolysis. The β-SiC and free C contents increased with the increasing dipping times, which cause some clear vibration and loss peaks of the dielectric constant patterns emerged at around 12.9 GHz and 14.7 GHz in the samples of 20 wt% and 30 wt% benzoic acid, respectively. The reflectivity of the obtained ceramics were −7dB ∼ −10dB from the frequency of 8 GHz–18 GHz, which means that the amount of 80%–90% electromagnetic wave could be attenuated. The ceramics containing 40 wt% benzoic acid showed the high loss, low reflectivity and a wide absorbing band, indicating the high absorbing efficiency and good dielectric properties.Graphical abstract
Source: Progress in Natural Science: Materials International - Category: Materials Science Source Type: research