Synthesis of large diamond crystals with C3H8N4O2 as organic additive under HPHT conditions

By temperature gradient method (TGM), with Invar alloy as solvent catalyst, FeS and boron as additives, large diamond crystals are grown under high pressure and high temperature (HPHT) of about 5.4GPa and 1550K. With the content of FeS increased, the colors of grown crystals would be changed from transparent yellow to opaque gray-black, and the quality of diamond crystals could also be destroyed markedly. When both boron and FeS co-doped, the negative effect of FeS on crystal quality could be eliminated somewhat. To a certain content of FeS, with the boron content increased, the crystal color would be changed from opaque gray-black to transparent yellow, and boron content needed is related directly to FeS content in growth systems. The nitrogen content in diamond lattice decreases greatly, with FeS content increased in the growth system, and a 1050cm-1 absorption peak in IR spectrum is also present in diamond crystals grown in FeNi-FeS-C system.

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Growth of Large Diamond Crystals by Reduction of Magnesium Carbonate with Metallic Sodium.

ChemInform ◽

10.1002/chin.200351015 ◽

2003 ◽

Vol 34 (51) ◽

Author(s):

Zhengsong Lou ◽

Qianwang Chen ◽

Wei Wang ◽

Yitai Qian ◽

Yufeng Zhang

Keyword(s):

Magnesium Carbonate ◽

Metallic Sodium ◽

Diamond Crystals ◽

Large Diamond

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Petrology of the Yubileynaya kimberlite pipe: application to the variation of kimberlites composition with the depth

10.5194/egusphere-egu2020-8541 ◽

2020 ◽

Author(s):

Zdislav Spetsius ◽

Alexander Ivanov

Keyword(s):

Lithospheric Mantle ◽

Original Data ◽

Kimberlite Pipe ◽

Essential Difference ◽

Mineral Phases ◽

Diamond Crystals ◽

Essential Input ◽

Indicator Minerals ◽

Different Levels ◽

Large Diamond

In this paper are summarized investigation results on the chemistry, petrography and mineralogy of kimberlitic rocks of the upper and deep levels of the Yubileynaya pipe. There are given original data on mineral phases contents in kimberlite ground mass,distribution of indicator minerals and olivine and its pseudomorphoses as well as autoliths (pyroclasts) in kimberlite drill cores of different levels (-)280 &#8211; (-)680m.Petrologic evidence suggest that for the kimberlites of the Yubileynaya pipe is characteristic the prevalence garnet association of indicator minerals with the relatively low their whole content, predominance oflherzolitic pyropes, low content of titanium garnets, two types of ilmenites and chromespinelides.The particularity of this pipe is the presence, both eclogite and garnet websterite xenoliths as well as their diamondiferous varieties. This evidence is confirmed also by the composition of the paragenic associations of indicator minerals that is indicative of essential difference of lithospheric mantle under this given pipe in contrast with nearby kimberlitic pipes. It is possible to speculate that these peculiarities are specific for the kimberlite pipes of the middle diamond productivity.Results of the garnets chemistry and the data of the distribution of eclogitic and ultramafic garnets in kimberlite concentrate of this pipe with the taking in account quantity of garnet variety potentially associated with diamonds suggest anincreased prevalence of eclogitic garnets among indicator minerals. This allowed making a statement about essential input of eclogitic paragenesis diamonds in the whole diamond production of this pipe. In our opinion these peculiarities also determine the increased content of large diamond crystals in kimberlites of the Yubileynaya pipe.&#160;&#160;&#160;&#160;

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Synthesis of large diamond single crystals under high pressure and high temperature through effective utilization of the synthesis cavity

CrystEngComm ◽

10.1039/c8ce00786a ◽

2018 ◽

Vol 20 (29) ◽

pp. 4127-4132 ◽

Cited By ~ 9

Author(s):

Yong Li ◽

Yadong Li ◽

Ying Wang ◽

Jie Zhang ◽

Mousheng Song ◽

...

Keyword(s):

High Pressure ◽

High Temperature ◽

Single Crystals ◽

Production Efficiency ◽

Effective Utilization ◽

Diamond Crystals ◽

Diamond Single Crystals ◽

Large Diamond

To make maximal use of the synthesis cavity and improve the production efficiency, we designed the double seed bed method to synthesize large diamond crystals under high pressure and high temperature (HPHT) conditions, and the results were both theoretically calculated and verified by experiments.

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