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Analysis of Valence Electron Theory on the Catalytic Mechanism of Diamond Single Crystal Growth

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Abstract:

Large numbers of experimental results show that carbides Me3C (Me means Fe, Ni, Co, Mn) are the primary carbon source to form diamond structure under the high temperature and high pressure (HPHT). In this paper, based on the empirical electron theory of solids and molecules (EET), the valence electron structure (VES) and interface structure factors of diamond and various carbides are calculated, and the boundary condition of electron movement in the improved Thomas- Fermi-Dirac theory by Cheng (TFDC) is applied to the carbide/diamond interfaces. It is found that the electron density of crystal plane in Me3C formed by C-C bonds is continuous with that in diamond at the first order of approximation. Compared with Ni-based carbides [Ni3C, (NiMn)3C)], the electron density difference of Fe-based carbides [Fe3C, (FeNi)3C, (FeMn)3C]/diamond interfaces is lower, and that of (FeNi)3C/diamond interface is minimum. The results show that the energy needed to transform carbon atomic groups into diamond structure is lower for Fe-based carbides than Ni-based carbides.

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Periodical:

Key Engineering Materials (Volumes 353-358)

Pages:

2998-3001

DOI:

https://doi.org/10.4028/www.scientific.net/KEM.353-358.2998

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Online since:

September 2007

Authors:

Li Li, Bin Xu, Mu Sen Li, Jian Hong Gong

Keywords:

Carbide, Catalytic Mechanism, Diamond, Valence Electron Theory

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© 2007 Trans Tech Publications Ltd. All Rights Reserved

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References

[1] B. L. Solozhenko and B. Z. Turkevich: Journal of Physical Chemistry. Vol. 106 (2002), p.6634.

Google Scholar

[2] E. Plvel, Gh. Baluta and D. Barb: Journal of Materials Science. Vol. 28 (1993), p.1645.

Google Scholar

[3] L. W. Yin, M. S. Li and J. J. Cui: Journal of Crystal Growth. Vol. 234 (2002) , p.1.

Google Scholar

[4] Z. L. Liu , Z. L. Li and W. D. Liu. Valence Electron Structure of Interfaces and their Properties. Beijing: Science Press (2002).

Google Scholar

[5] Z. L. Liu, Z. L. Li and Z. G. Sun: Metallurgical and Materials Transactions. A (1999), p.2757.

Google Scholar

[6] B. Xu, Li M S and Cui J J: Material Science & Engineering. Vol. 396(2005), p.352.

Google Scholar

[7] B. Xu, J. J. Cui and M. S. Li: China Physical Letter. Vol. 2 (2005), p.478.

Google Scholar

[8] Z. Y. Hao and Y. F. Chen: Synthetic Diamond. Changchun: Jilin University Press (1996), p.95.

Google Scholar