【摘要】 本文报道在机械驱动力下 ,通过机械合金化途径使氮或氨直接在室温下在逐步细化的、新鲜的、高反应活性的硅界面上充分扩散 ,形成亚稳态系统 ,在 80 0℃真空炉处理后得到纳米 α- Si3 N4粉末。发现气氛对合成 Si3 N4纳米粉末有很大影响。在氮气中 ,高能球磨前硅粉表面形成的氧化膜在高能球磨过程中与氮反应生成 Si2 N2 O保护层 ,阻止氮的进一步扩散 ,使反应产物含有大量未反应的游离硅。在氨气中可以避免生成 Si2 N2 O,反应产物几乎全部转化为α- Si3 N4。更多还原

【Abstract】 Under mechanical power nitrogen or ammonia was fully diffused on progressively fine, fresh,highly active interfaceofsilicon by use ofthe mechanical alloy method,forming a sub- stable system. The nanometerα- Si3 N4was obtained after heat- treated in vacuum furnace at 80 0℃ . It was found that the atmosphere effects on the synthesis of nanometer Si3 N4powder greatly.In nitrogen gas,the protective layerof Si2 N2 O was produced through the reaction of nitrogen with oxidic film formed on the face of silicon powder before mill,which prevented nitrogen from progressively diffusing,resulting in a lot of non- reaction free silicon in prod- uct.In ammonia gas,the formation of Si2 N2 O was avoided.The product was nearly com- pletelyα- Si3 N4.更多还原