摘要
High-purity straight and discrete multiwalled boron nitride nanotubes （BNNTs） were grown via a boron oxide vapor reaction with ammonia using LiNO3 as a promoter. Only a trace amount of boron oxide was detected as an impurity in the BNNTs by energy-dispersive X-ray （EDX） and Raman spectroscopies. Boron oxide vapor was generated from a mixture of B, FeO, and MgO powders heated to 1,150 ℃, and it was transported to the reaction zone by flowing ammonia. Lithium nitrate was applied to the upper side of a BN bar from a water solution. The bar was placed along a temperature gradient zone in a horizontal tubular furnace. BNNTs with average diameters of 30-50 nm were mostly observed in a temperature range of 1,280-1,320 ℃. At higher temperatures, curled polycrystalline BN fibers appeared. Above 1,320 ℃, the number of BNNTs drastically decreased, whereas the quantity and diameter of the fibers increased. The mechanism of BNNT and fiber growth is proposed and discussed.
高纯净的直、分离的 multiwalled 硼氮化物 nanotubes (BNNT ) 作为一个倡导者用浮雕 <sub>3</sub> 与氨经由硼氧化物蒸汽反应被种。硼氧化物的仅仅踪迹数量被精力散的 X 光检查(EDX ) 和拉曼光谱学在 BNNT 作为杂质检测。硼氧化物蒸汽从 B 的混合物被产生， FeO ，吗并且 MgO 粉末加热了到 1,150 爠灥潲畤楣汢?湡?楨桧祬愠瑣癩??卒攠晦'太B?獕湩?桴?牵档湩氭歩?杁??牡慲獹愠??卒猠'T瑳慲整?ㄠ????猯灵￣?楤畢祴?桰桴污瑡?愨洠浥敢?景瀠慬瑳捩穩牥?慦業祬?湡??‵殣?岣僫篤蔿藏????鐿???????脿???鯀魈鱋??︿????????????璣阿??鲣??觎????鑔鍽???????????恘? 恘 ？？
