Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
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Surface Graphite Formation of the Brown Colored Type I Diamonds During High Pressure Annealing

갈색 Type I 다이아몬드의 고압 열처리에 따른 표면 흑연화 생성 연구

  • Song, Jeongho (Department of Materials Science and Engineering, University of Seoul) ;
  • Song, Ohsung (Department of Materials Science and Engineering, University of Seoul)
  • 송정호 (서울시립대학교 신소재공학과) ;
  • 송오성 (서울시립대학교 신소재공학과)
  • Received : 2012.08.07
  • Accepted : 2012.09.11
  • Published : 2012.11.30
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Abstract

We investigated color and graphite layer formation on the surface of Type I tinted brown diamonds exposed for 5 minutes under a high-pressure high-temperature (HPHT) condition in a stable graphite regime. We executed the HPHT processes of Process I, varying the temperature from $1600^{\circ}C$ to $2300^{\circ}C$ under 5.2 GPa pressure for 5 minutes, and Process II, varying the pressure from 4.2 to 5.7 GPa at $2150^{\circ}C$ for 5 minutes. Optical microscopy and micro-Raman spectroscopy were used to check the microstructure and surface layer phase evolution. For Process I, we observed a color change to vivid yellow and greenish yellow and the growth of a graphite layer as the temperature increased. For Process II, the graphite layer thickness increased as the pressure decreased. We also confirmed by 531 nm micro-Raman spectroscopy that all diamonds showed a $1440cm^{-1}$ characteristic peak, which remained even after HPHT annealing. The results implied that HPHT-treated colored diamonds can be distinguished from natural stones by checking for the existence of the $1440cm^{-1}$ peak with 531 nm micro-Raman spectroscopy.

Keywords

References

  1. G. E. Harlow, "The Nature of Diamonds, American Museum of Natural History," pp. 214-72, Cambridge University Press, New York, 1998.
  2. A. V. Nikiin, M. I. Samoilovich, G. N. Bezrukov, and K. F. Vorozheikin, "The Effect of Heat and Pressure on Certain Physical Properties of Diamonds," Sov. Phys. Dokl., 13 842-44 (1968).
  3. T. Evans and P. Rainey, "Changes in the Defect Structure of Diamond due to the High Temperature High Pressure Treatment," Proc. Royal Soc., 344 111-30 (1975). https://doi.org/10.1098/rspa.1975.0093
  4. R. M. Chrenko, R. E. Tuft, and H. M. Strong, "Transformation of the State of Nitrogen in Diamond," Nature, 270 141-44 (1977). https://doi.org/10.1038/270141a0
  5. Vagarali, "High Pressure/High Temperature Production of Colorless and Fancy-Colored Diamonds (in USA)," Eng. Patent, US7323156, 2008.
  6. F. Li, "Color Enhancement of Natural Brown Tinted Diamonds by HPHT," pp. 123-4, M.S. Thesis, University of Seoul, 2011.
  7. M. Perraki, A. Proyer, E. Mposkos, R. Kaindl, and G. Hoinkes, "Raman Micro-Spectroscopy on Diamond, Graphite and Other Carbon Polymorphs from the Ultrahigh-Pressure Metamorphic Kimi Complex of the Rhodope Metamorphic Province, NE Greece," Earth Planet Sci. Lett., 241 672-85 (2006). https://doi.org/10.1016/j.epsl.2005.11.014
  8. F. Li, Y. Shen, H. M. Choi, Y. C. Kim, and O. S. Song, "The Color Enhancement of Brown Tinted Diamonds with Annealing Time in HPHT," J. Kor. Gems and Jewelry, 5 [1] 1-6 (2011).
  9. D. A. Porter, K. E. Easterling, M. Y. Sherif, "Phase Transformations in Metals and Alloys-Third Edition," pp. 31-41, CRC Press, New York, 2008.
  10. F. Li and O. S. Song, "The Color Enhancement of Brown Tinted Diamonds with Annealing Temperatures in 5.6 GPa- 10min HPHT," Kor. J. Met. Mater, 50 [1] 23-7 (2012). https://doi.org/10.3365/KJMM.2012.50.1.023

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