采用双反应室激光气相合成纳米粉体装置,以六甲基二硅胺烷((Me3Si)2NH)(Me:CH3)为原料合成了纳米Si/C/N复相粉体,粒径为20 nm～30 nm.研究了纳米Si/C/N复相粉体在8.2 GHz～18 GHz的微波吸收特性,结果表明:纳米Si/C/N复相粉体介电常数的实部(ε′)和虚部(ε″)在8.2 GHz～18 GHz随频率增大而减小,介电损耗(tgδ=ε″/ε′)较高,是较为理想的微波吸收材料;纳米Si/C/N复相粉体在不同基体中的微波吸收特性出现很大差异.纳米Si/C/N复相粉体中的SiC微晶固溶了大量的N原子,形成大量带电缺陷,极化弛豫是吸收微波的主要原因.根据纳米Si/C/N复相粉体与石蜡复合体的实测介电参数,设计出多组在8 GHz～18 GHz范围内微波反射系数R≤-8dB的吸波涂层结构.
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