摘要
着重研究了添加剂对自蔓延高温合成AlN中的含氧量增加的影响 ,讨论了AlN形态与含氧量之间的关系 .疏松剂NH4 Cl虽可使得产物疏松 ,易于破碎 ,但它增加了体系中水蒸汽量 ,促进AlN中含氧量的增加 .碳的存在可降低体系中的水蒸汽量 ,使NH4 Cl对产物中含氧量的促进作用受到抑制 .部分碳化的蔗糖在自蔓延过程中发生碳化 ,可获得较大的表面积 ,使得其较明显地抑制含氧量的增加 .在自蔓延高温合成过程中 ,AlN的含氧量与其形态关系密切 .含氧量高的AlN倾向于形成晶须 ,而含氧量低的AlN倾向于形成颗粒状 .AlN晶须以固 -液 -气 (VLS)机制生长 .VLS机制所需液相的生成与氧有关 .液相产生所需的氧应主要来自气体中的含氧杂质(氧气和水蒸汽 ) .
Effect of additives on the oxygen content and morphology of SHS AlN is focused in the study. The NH 4Cl additive made the product loosen. However, it promotes the increase of oxygen content in the product at the same time. Small amount of carbon can decrease the effect of NH 4Cl. Partly carbonized sucrose can significantly decrease the oxygen content in the product due to its larger surface area, which resulted from its carbonization in the combustion area. The morphology of AlN is related to its oxygen content. AlN trends to form particle at the low_oxygen atmosphere, and inclined to grow in the form of whiskers by the vapour-liquid-solid(VLS) mechanism at the atmosphere of high_oxygen. The formation of liquid, required by the VLS mechanism, depended on moisture and oxygen in the nitrogen.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2000年第1期15-19,共5页
Journal of The Chinese Ceramic Society
关键词
自蔓高温合成
氮化铝
助剂
电子材料
self_propagating high_temperature synthesis(SHS)
aluminium nitride
additive
