Effects of additive NaN3 on the HPHT synthesis of large single crystal diamond grown by TGM
Effects of additive NaN3 on the HPHT synthesis of large single crystal diamond grown by TGM
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DOI：
10.1007/s11433-010-4129-4
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发表时间：
2010-09
期刊：
影响因子：
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通讯作者：
Guofeng Huang;X. Jia;Shangsheng Li;Meihua Hu;Yong Li;Ming Zhao;B. Yan;Hong-an Ma
中科院分区：
文献类型：
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作者：
Guofeng Huang;X. Jia;Shangsheng Li;Meihua Hu;Yong Li;Ming Zhao;B. Yan;Hong-an Ma
本文采用温度梯度法（TGM）在高温高压条件下成功地合成了氮含量约为1671-1742ppm、形状完整的大单晶金刚石。HPHT合成条件约为5.5GPa和1500 - 1550 K。在高纯石墨和可伐合金的合成体系中加入不同含量的叠氮化钠（NaN3）作为氮源。研究了添加剂NaN3对晶体生长习性的影响。采用扫描电镜（SEM）和红外光谱（IR）对合成金刚石的晶体形貌、氮含量及存在形式进行了表征。结果表明，随着合成体系中NaN3含量的增加，合成高质量金刚石的温度范围变窄，晶体生长速率受到限制，而合成金刚石中的氮浓度增加。氮在金刚石中主要以分散形式（C中心）和部分聚集形式（A中心）存在。当合成体系中加入过量的NaN3时，晶体表面缺陷的出现频率更高。
In this paper, large single crystal diamond with perfect shape and high nitrogen concentration approximately 1671–1742 ppm was successfully synthesized by temperature gradient method (TGM) under high pressure and high temperature (HPHT). The HPHT synthesis conditions were about 5.5 GPa and 1500–1550 K. Sodium azide (NaN3) with different amount was added as the source of nitrogen into the synthesis system of high pure graphite and kovar alloy. The effects of additive NaN3on crystal growth habit were investigated in detail. The crystal morphology, nitrogen concentration and existing form in synthetic diamond were characterized by means of scanning electron microscope (SEM) and infrared (IR) absorption spectra, respectively. The results show that with an increase of the content of NaN3added in the synthesis system, the region of synthesis temperature for high-quality diamond becomes narrow, and crystal growth rate is restricted, whereas the nitrogen concentration in synthetic diamond increases. Nitrogen exists in diamond mainly in dispersed form (C-centers) and partially aggregated form (A-centers). The defects occur more frequently on crystal surface when excessive NaN3is added in the synthesis system.