| Original Articles |
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Twins Diamond Crystals Grown at High Temperature and High
Pressure from the Fe-Ni-C System
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| YIN Long-Wei1;YUAN Quan2;LI Mu-Sen1;LIU Yu-Xian1;XU Bin1;HAO Zhao-Yin3 |
| 1College of Materials Science and Engineering, Shandong University, Ji’nan 250061
2College of Mechanical Science and Engineering, Shandong University, Ji’nan 250061
3National Key Laboratory for Superhard Materials, Jilin University, Changchun 130012
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| Cite this article: |
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YIN Long-Wei, YUAN Quan, LI Mu-Sen et al 2002 Chin. Phys. Lett. 19 1371-1373 |
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Abstract Twin diamond crystals grown at high temperature and high pressure (HPHT) in the presence of FeNi catalyst have been xamined by transmission electron microscopy (TEM). Direct observation by TEM shows that there are a large amount of twins which lie on the {111} planes in the HPHT-grown diamonds. The twins in the diamond may be formed and may extend into the inner crystal from the twin nucleus formed in the nucleation process. The twins can be formed due to the carbon atoms falling mistakingly into positions where a twin crystal can form during diamond growth, or condensation of supersaturated vacancies on the {111} plane. Some hexagonal dislocation loops related to supersaturated vacancies are found on the twins. The Moiré fringe image reveals that stacking faults terminate on intersecting twin boundary. This suggests that, at the temperature that the HPHT diamond is grown, the bordering partial has propagated by gliding up to the twin interface, which can be described by the reaction of a Shockley partial dislocation with a twin on the {111} plane.
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| Keywords:
81.05.Uw
61.72.Ff
68.37.Lp
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Published: 01 September 2002
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| PACS: |
81.05.Uw
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61.72.Ff
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(Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.))
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68.37.Lp
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(Transmission electron microscopy (TEM))
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