摘要
分别用硼砂和氯化铵、硼砂和尿素为原料，在９５０ ℃下合成出 ２种结晶度相近、平均颗粒度分别为５．６×１０－６和 １．４２×１０－６ｍ的ｈＢＮ．在高温高压条件下，使用锂系催化剂，由前１种ｈＢＮ合成的ｃＢＮ为黄色透明体，由后一种ｈＢＮ合成的ｃＢＮ大部分为黑色半透明体，并且在ｃＢＮ晶体表面上观察到生长台阶．以硼氢化钾和氯化铵为原料合成出的ｈＢＮ为无定形态，平均颗粒度为１２．４３×１０－６ｍ，使用锂系催化剂，该ｈＢＮ未能合成出ｃＢＮ．探讨了ｃＢＮ的形成机制．
Two kinds of hBN were synthesized by using Na2B4O7-NH4Cl and Na2B4O7-(NH)2CO as the starting materials at 950 , both hBN are analogous in crystallization, the average particle size was 5.6 and 1 .42 um respectively. Under high temperature and high Pressure and using Li series catalysts, cBN synthesized from the former was yellow transparent and from the latter showed black translucent. It is also found that growth stops on the surface of cBN crystals occur.The hBN obtained from the reaction of KBH4 and NH4Cl is amorphous with particle size of 12.43 um, and it can not transform into cBN using Li series catalysts. The synthesis mechanism of cBN was discussed.
出处
《北京科技大学学报》
EI
CAS
CSCD
北大核心
2001年第4期337-339,共3页
Journal of University of Science and Technology Beijing
基金
国家自然科学基金资助课题(No.59972003)
关键词
六方氮化硼
立方氮化硼
合成
hexagonal boron nitride
cubic boron nitride
synthesis
