Effect of SiBCN content on the dielectric and EMW absorbing properties of SiBCN-Si3N4 composite ceramics. Issue 4 (April 2018)

• Record Type: Journal Article
• Authors: Zhao, Mingxi; Liu, Yongsheng; Chai, Nan; Qin, Hailong; Liu, Xiaofei; Ye, Fang; Cheng, Laifei; Zhang, Litong
• Is Part Of: Journal of the European Ceramic Society. Volume 38:Issue 4(2018)
• Page Start: 1334
• Page End: 1340
• Publication Date: 2018-04
• Subjects: Siliconboron carbonitride ceramics -- Dielectric properties -- Electromagnetic wave absorbing properties -- Chemical vapor deposition and infiltration; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2017.10.021
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: Siliconboron carbonitride ceramics (SiBCN) were introduced into porous Si3 N4 substrates via low pressure chemical vapor deposition and infiltration from SiCl3 CH3 -NH3 -BCl3 -H2 -Ar system. To improve the electromagnetic wave(EMW) absorbing properties, the molar ratio, nCH3SiCl3 /(nNH3 + nBCl3 ), was increased based on thermodynamics analysis. The results show that nanosized silicon carbide crystals and free carbon dispersed uniformly in the amorphous SiBCN phase, resulting in suitable dielectric properties and improved absorption capabilities of SiBCN-Si3 N4 ceramics. Additionally, with increasing SiBCN ceramics loading, the amount of nanocrystals and interface between nanocrystals and amorphous SiBCN phase increased, leading to enhanced polarization and dielectric loss of the composite ceramics. When SiBCN content was up to 3.64 wt%, the electromagnetic reflection coefficient (RC) of SiBCN-Si3 N4 composite ceramics reached −40 dB (>99.97% absorbing) with the effective electromagnetic absorbing bandwidth of 3.64 GHz in the X-band. This study makes it possible to fabricate SiBCN-based composite materials with excellent EMW absorbing properties at a low temperature.