以尿素为氮源合成AlN粉体过程中非晶碳的石墨化

针对有机合成过程中碳及碳化物的残余,传统方法中普遍使用除碳的工艺,而很少有文章针对非晶碳的结构和形貌进行表征。为此,本文采用高尿素含量的前驱盐体系,通过在氮气保护气氛中煅烧获得AlN粉体。采用X射线衍射分析、红外和拉曼光谱分析、扫描电子显微镜和透射电子显微镜对850~1 500 ℃温度范围内煅烧获得产物的结构和形貌进行表征,对AlN合成过程中含碳产物结构形貌的变化,以及AlN和含碳产物之间相互的依存生长关系进行分析。结果表明,AlN生长的过程中伴随着无定形碳的石墨化转变,AlN颗粒的形貌也受含碳残余产物形貌的影响而出现有规律的变化。

Graphitization of Amorphous Carbon During Synthesis of AlN Powder with Urea as Nitrogen Source

The residual carbon and carbides were typical phenomenon in the ceramic powder synthesis by a chemical way. The carbon removal process is commonly used, but there were few articles referred to the structure and morphology of residual carbon. In this paper, a precursor salt system with high urea content was adopted to prepare AlN powder by calcination in a nitrogen protective atmosphere. The structure and morphology of the products obtained by calcination in the temperature range from 850 ℃ to 1 500 ℃ were characterized by X-ray diffraction, infrared and Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. Meanwhile, the changes in the structure and morphology of carbon-containing products during the synthesis of AlN, and the interdependent growth relationship between AlN and carbon-containing products were analyzed. The results show that the graphitization transformation of amorphous carbon is accompanied by the growth of AlN, and the morphology of AlN particles is also affected by the morphology of carbon-containing residual products.