用NiMnCo触媒合成优质Ⅱa型金刚石大单晶  

Synthesising large high-quality type Ⅱa gem diamonds with NiMnCo catalyst

作　　者：李尚升[1] 马红安[2] 臧传义[1] 李小雷[1] 田宇[2] 张亚飞[2] 肖宏宇[2] 尹斌华[1] 贾晓鹏[1] 

机构地区：[1]河南理工大学材料科学与工程学院,河南焦作454000 [2]吉林大学超硬材料国家重点实验室,吉林长春130012

出　　处：《金刚石与磨料磨具工程》2006年第2期16-18,共3页Diamond & Abrasives Engineering

基　　金：国家自然科学基金项目资助(50572032)

摘　　要：用NiMnCo触媒利用温度梯度法在高温高压下合成优质Ⅱa型宝石级金刚石。研究发现在约5．5GPa和1230℃的条件下，除氮剂Ti（Cu）的加入使合成金刚石的温度区间下限抬高而变窄，因而在设备控制精度符合要求的条件下实验解决了组装的稳定性问题；与此同时Ti（Cu）的加入也使金刚石晶体生长过程中更易俘获包裹体而出现熔坑，从而影响晶体的生长速度。本文分析了Ti（Cu）掺入量对晶体生长速度的影响。实验表明合成无色Ⅱa型宝石级金刚石合适的Ti（Cu）掺入量为1．8wt％。降低生长速度使包裹体和熔坑问题得到解决。实验获得了-4mm的优质Ⅱa型金刚石大单晶。红外测试分析表明该金刚石含氮量小于1×10^-6。High-quality type Ⅱ a gem diamonds were synthesized by means of temperature-gradient-method with NiMnCo catalyst under high pressure and high temperature. While the nitrogen getter Ti （Cu） is added, at ～ 5.5GPa and - 1230℃ ,the temperature range of diamond synthesis become narrower, then a stable assembly at high controlling precision of the equipment was realized ; At the same time, the diamonds become liable to trap the metal inclusions and to leave cavities on the crystals. So the effect of Ti （Cu） on the growth rate of diamonds was obvious. The effect of the amount of Ti （Cu） on the growth rate of diamonds was also analyzed in this paper. Experiments show that the appropriate amount of Ti （Cu） is 1.8 wt% in the synthesis of the colorless type Ⅱ a gem diamonds. The problems of the inclusions and cavities were solved. High-quality type Ⅱ a gem diamonds with size ～ 4 mm were synthesized. The nitrogen concentration in the diamond which was measured by FFIR （ Fourier Transform Infrared） is less than 1×10^-6.

关 键 词：NiMnCo触媒 Ⅱa型宝石级金刚石 温度梯度法 生长速度 

分 类 号：TQ164[化学工程—高温制品工业]