Si/C/N纳米粉体的吸波特性研究

采用XRD研究了氮原子百分含量为11．61％的Si/C/N纳米粉体的相组成，并测定了测粉体介电常数根据介电常数，分别优化调离了单层和双层的吸波涂层，设计的吸波涂层对8－18GHz范围的电磁波有较好的吸收作用，设计厚度为2．7mm的单层吸波涂层，在8－5GHz范围内反射率＜－5dB，设计厚度为2．8mm的双层吸波涂层，在8－18GHz频率范围内电磁波的反射率均＜－5dB，反射率＜－8dB的频带为6GHz，针对纳米粉体的吸波特性，提出了Si/C/N纳米粉体的吸波机理。

Dielectric Properties of Si/C/N Nano Powders

Si/C/N nano powders with 11.61% nitrogen were prepared by CVD. XRD pattern and permittivity of the powders were investigated. On the basis of permittivity of the powders, radar absorber structures of single- and double-layer were designed. A single-layer absorber coating with a reflection coefficient less than -5dB in the frequency range of 8-15GHz was designed with a thickness of 2.7mm. A double-layer radar absorber coating with a reflection coefficient less than -5dB in the frequency range of 8-18GHz was also designed with a thickness of 2.8mm. The range of the reflection coefficient being less than -8dB was 6GHz for the designed double-layer radar absorber. The radar absorbing mechanism of Si/C/N nano powders was also interpreted. The SiC microcrystalline in the nano composite powder dissolves a great deal of nitrogen. The charged defects are caused by N atoms occupying the sites of C in SiC moved in response to the electric field. The dielectric relaxation caused by the charged defects moved in response to the electric field is the main way of the Si/C/N nano powders with absorbing properties.