Synthesis of large diamond crystals containing high-nitrogen concentration at high pressure and high temperature using Ni-based solvent by temperature gradient methodHuang Guo-Feng1, Jia Xiao-Peng1,2, Li Shang-Sheng2,

• 来源期刊: 中国物理B（英文版）
• 关键词: high temperature and high pressure nitrogen-doped diamond crystal temperature gra-dient method additive NaN3
• 年，卷（期）: 2010,（11）
• 页码范围: 662-666
• 页数: 5页
• 语种: 英文

摘要

This paper reprots that with Ni-based catalyst/solvent and with a dopant of NaN3>, large green single crystal diamonds with perfect shape are successfully synthesized by temperature gradient method under high pressure and high temperature in a China-type cubic anvil high-pressure apparatus (SPD-6×1200), and the highest nitrogen concentration reaches approximately 1214-1257 ppm calculated by infrared absorption spectra. The synthesis conditions are about 5.5 GPa and 1240-1300℃. The growth behaviour of diamond with high-nitrogen concentration is investigated in detail. The results show that, with increasing the content of NaN3> added in synthesis system, the width of synthesis temperature region for growth high-quality diamonds becomes narrower, and the morphology of diamond crystal is changed from cube-octahedral to octahedral at same temperature and pressure, the crystal growth rate is slowed down,nevertheless, the nitrogen concentration doped in synthetic diamond increases.