| Original Articles |
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Effect of Regrown Graphite on the Growth of Large Gem Diamonds by Temperature Gradient Method |
| ZANG Chuan-Yi;JIA Xiao-Peng;MA Hong-An;TIAN Yu;XIAO Hong-Yu |
| The National Key Laboratory for Superhard Materials, Jilin University, Changchun 130012 |
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| Cite this article: |
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ZANG Chuan-Yi, JIA Xiao-Peng, MA Hong-An et al 2005 Chin. Phys. Lett. 22 2415-2417 |
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Abstract Generally, when growing high-quality large gem diamond crystals by temperature gradient method under high pressure and high temperature, the crystal growth rate is only determined by the temperature gradient. However, we find that the seed crystal cannot completely absorb all the diffused carbon sources, when growing gem diamonds under a higher temperature gradient. Other influence factors appear, and the growth rate of growing diamonds is partly dependent on the crystalline form of superfluous unabsorbed carbon source, flaky regrown graphite or small diamond crystals nucleated spontaneously. The present form is determined by the growth temperature if the pressure is fixed. Different from spontaneous diamond nuclei, the appearance of regrown graphite in the diamond-stable region can retard the growth rate of gem diamonds substantially, even if the temperature gradient keeps unchanged. On the other hand, the formation mechanism of metastable regrown graphite in the diamond-stable region is also explained.
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| Keywords:
81.05.Uw
81.10.Aj
81.10.Dn
81.10.-h
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Published: 01 September 2005
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| PACS: |
81.05.Uw
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81.10.Aj
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(Theory and models of crystal growth; physics and chemistry of crystal growth, crystal morphology, and orientation)
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81.10.Dn
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(Growth from solutions)
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81.10.-h
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(Methods of crystal growth; physics and chemistry of crystal growth, crystal morphology, and orientation)
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