Log in

Relevant bibliographies by topics / Synthetic diamonds / Journal articles

To see the other types of publications on this topic, follow the link: Synthetic diamonds.

Journal articles on the topic 'Synthetic diamonds'

Author: Grafiati

Published: 30 May 2022

Last updated: 31 May 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Synthetic diamonds.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Negmatova, Kamola, Abdusattor Daminov, Abdusalam Umarov, and Nodira Аbed. "Synthesis of diamonds in the C – Mn - Ni - (H) system and the diamond-shaped mechanism." E3S Web of Conferences 264 (2021): 05003. http://dx.doi.org/10.1051/e3sconf/202126405003.

Full text

Abstract:

Studying the dependence of the degree (α) and rate (ϑ) of the phase transformation of graphite into diamond on the synthesis time at different temperatures of the developed synthetic diamonds using the technology of high-pressure high-temperature synthesis in a metal melt (HPHT), we determined the critical mass of diamonds, which indicates the entry of the system into the stability region of graphite, where the graphitization of diamonds occurs. The role of implanted metals and hydrogen in the formation of synthetic diamonds and on its properties was also investigated.

APA, Harvard, Vancouver, ISO, and other styles

2

Lu, Qi, Huaiyu Gong, Qingfeng Guo, Xuren Huang, and Jiayi Cai. "Gemological Characteristic Difference between Colorless CVD Synthetic Diamonds and Natural Diamonds." Materials 14, no. 20 (October 19, 2021): 6225. http://dx.doi.org/10.3390/ma14206225.

Full text

Abstract:

CVD synthetic diamond plays an important role in the jewelry market due to its excellent performance and low cost. In this paper, colorless CVD synthetic diamonds produced by a Chinese company were investigated in detail with their gemological, spectroscopic, and luminescent properties compared with natural colorless diamonds. Compared with natural diamonds, CVD synthetic diamonds have high-order interference color and more apparent abnormal birefringence. The results of infrared spectra indicate that all the CVD samples are classified as type IIa, while the natural samples belong to type Ia. The CVD samples show lamellar growth and mottled luminescence pattern and have blue, orange red, purple red, and blue fluorescence, respectively, while most of the natural samples show blue fluorescence. CVD diamonds show lamellar growth structure, and natural diamonds show irregular ring-like growth structure. Thus, multiple methods combined with analysis are required to distinguish synthetic diamonds from natural diamonds. This work provides an experimental basis for the identification of CVD synthetic diamonds.

APA, Harvard, Vancouver, ISO, and other styles

3

Tomilenko, Anatoly A., Anatoly I. Chepurov, Yury N. Pal' Yanov, Anatοly P. Shebanin, and Nikolai V. Sobolev. "Hydrocarbon inclusions in synthetic diamonds." European Journal of Mineralogy 10, no. 6 (December 1, 1998): 1135–42. http://dx.doi.org/10.1127/ejm/10/6/1135.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Tillmann, Wolfgang, and Artur Martin Osmanda. "Production of Diamond Tools by Brazing." Materials Science Forum 502 (December 2005): 425–30. http://dx.doi.org/10.4028/www.scientific.net/msf.502.425.

Full text

Abstract:

Diamond tools are increasingly gaining importance as cutting materials for various construction materials. The quality of synthetic diamonds, monocrystalline as well as polycrystalline or CVD-diamonds has been significantly improved over the last years. Integrating these cutting materials requires adequate joining technologies that produce sound joints without exposing the temperature sensitive diamond to too elevated temperatures. The paper highlights current developments in the joining of synthetic diamonds to steel. Owing to their covalent atomic bonding diamonds cannot easily be wetted and joined by employing conventional brazing alloys. Hence, active agents are needed to foster an interfacial reaction. Different active filler concepts are presented and discussed regarding their joint formation. The brazing temperatures influence not only possible diamond degradation but also the interfacial decomposition of the diamond due to the formation of corresponding reaction layers.

APA, Harvard, Vancouver, ISO, and other styles

5

Polushin, Nikolay Ivanovich, Alexander Ivanovich Laptev, Mariya Stanislavovna Shitareva, Dmitry Sergeevich Muratov, Anatoly Lvovich Maslov, Alexey Nikolaevich Kirichenko, Sergey Alexeevich Perfilov, and Tatiana Vladimirovna Martynova. "The use of spectroscopy methods for structural analysis of CVD diamond films, polycrystalline and single-crystal diamonds." MATEC Web of Conferences 336 (2021): 01013. http://dx.doi.org/10.1051/matecconf/202133601013.

Full text

Abstract:

For the work results correct interpretation, it is important to study initial materials that scientists have to deal with. Currently, there are a large number of different diamond substrates. Comparison of materials among themselves allows you to determine which material you are dealing with. In this work, the methods of infrared (IR) spectrometry, Raman spectroscopy and spectrophotometry are used to study four types of diamond materials: diamond polycrystalline CVD-films; natural single-crystal diamonds; synthetic polycrystalline HPHT-diamonds (such as DSPC – diamond synthetic polycrystal by GOST 9206-80); polycrystalline CVD-diamonds CDM manufactured by E6. In work it was shown that the Raman spectroscopy allows to measure the effect of heat treatment on changes in the diamond structure, even if it is such highly advanced diamond materials as natural diamonds. Heat treatment affects the perfection of diamond crystal structure by reducing stresses and the number of defects in it due to graphitization process. The IR spectrometry method is effective for determining the shape and amount of nitrogen inclusions in diamond structure. To study polycrystalline CVD-films, the spectrophotometry method turned out to be the most effective, because it made possible to determine a small number of nitrogen defects and draw conclusions about the quality of the films. The investigation of polycrystalline diamonds CDM and DSPC demonstrated that, despite their coarse-crystalline structure, diamond crystallites consist of a highly defective diamond phase; in addition, DSPC-diamonds were studied using this method in the first time.

APA, Harvard, Vancouver, ISO, and other styles

6

Litasov, Konstantin D., Hiroyuki Kagi, Tatyana B. Bekker, Yoshiki Makino, Takafumi Hirata, and Vadim V. Brazhkin. "Why Tolbachik Diamonds Cannot be Natural." American Mineralogist 106, no. 1 (January 1, 2021): 44–53. http://dx.doi.org/10.2138/am-2020-7562.

Full text

Abstract:

Abstract Taking into account recent publications, we provide additional comprehensive evidence that type Ib cuboctahedral diamonds and some other microcrystalline diamonds from Kamchatka volcanic rocks and alluvial placers cannot be natural and undoubtedly represent synthetic materials, which appear in the natural rocks by anthropogenic contamination. The major arguments provided in favor of the natural origin of those diamonds can be easily disproved. They include the coexistence of diamond and deltalumite from Koryaksky volcano; coexistence with super-reduced corundum and moissanite, Mn-Ni silicide inclusions, F-Cl enrichment and F/Cl ratios, and carbon and nitrogen isotopes in Tolbachik diamonds, as well as microtwinning, Mn-Ni silicides, and other inclusions in microcrystalline diamond aggregates from other Kamchatka placers. We emphasize the importance of careful comparison of unusual minerals found in nature, which include type Ib cuboctahedral diamonds and super-reduced phase assemblages resembling industrial slags, with synthetic analogs. The cavitation model proposed for the origin of Tolbachik diamonds is also unreliable since cavitation has only been shown to cause the formation of nanosized diamonds only.

APA, Harvard, Vancouver, ISO, and other styles

7

Rashmi, Nahar Singh, and A. K. Sarkar. "Application of the Rietveld method to quantitative analysis of impurities in synthetic diamond powder." Powder Diffraction 19, no. 2 (June 2004): 141–44. http://dx.doi.org/10.1154/1.1648314.

Full text

Abstract:

Synthetic diamonds are an important class of industrial material. During synthesis impurities may get introduced into diamond. Identification and quantification of impurities is important as they affect the properties and suitability of the diamonds for their application. Impurities in an industrial synthetic diamond powder sample were analyzed by X-ray diffraction (XRD) and also by chemical methods. X-ray diffraction pattern showed diamond as the major phase and α-iron as a minor phase. Quantitative analysis of crystalline phases was done by performing Rietveld refinement of the XRD profile. Chemical analysis showed the presence of several other impurities as well, though in small amounts. It was considered that the impurities other than iron were in amorphous form and an estimate of the amorphous content was made on this basis. Relative phase composition of diamond and iron as estimated by XRD were corrected for the amorphous content to obtain absolute phase composition.

APA, Harvard, Vancouver, ISO, and other styles

8

Зиенко, С. И., and Д. С. Слабковский. "Особенности фононного крыла люминесценции алмаза." Письма в журнал технической физики 45, no. 11 (2019): 9. http://dx.doi.org/10.21883/pjtf.2019.11.47815.17761a.

Full text

Abstract:

It is experimentally established that the luminescence spectrum of diamond at room temperature contains one or two peaks in the form of Gauss curves. This result is related to the exciton-phonon interaction in diamond, which, along with the zero-phonon line, contains first and second order phonon repetitions. This phenomenon is typical only for natural diamonds and is absent in synthetic samples. Therefore, it can be used to identify cut diamonds (diamonds).

APA, Harvard, Vancouver, ISO, and other styles

9

Badzian, Andrzej R. "Defect Structure of Synthetic Diamond and Related Phases." Advances in X-ray Analysis 31 (1987): 113–28. http://dx.doi.org/10.1154/s0376030800021911.

Full text

Abstract:

AbstractThis paper examines the relationship between the lattice defects and crystallization process of synthetic diamonds. Diamonds synthesized by high pressure, high temperature methods as well as diamonds vapor deposited under metastable conditions are considered. High pressure crystals precipitated from Ni or Co solutions contain inclusions of metastable carbides and metal atoms distributed throughout a small fraction of the octahedral holes in the diamond lattice.Diamonds are grown metastabily by a chemical vapor deposition process in which CH4 and H2 are excited by a microwave plasma. Such diamonds are deposited as individual micro-monocrystals or as solid poly crystalline films. The defects in such crystals are related to impurities such as Si and H which produce point defects and tend to nucleate graphite, which can generate planar defects. Nucleation of a diamond phase on β-SiC is also considered, because of the lattice matching between them.Diamond structure is a prototype of a family of related phases such as cubic BN (sphalerite structure) and solid solutions of diamond and cubic BN, Cubic BN-diamond solid solutions (BN)x(C2)1-x,0<x<l are, in turn, a prototype of AIIIBV-CIV phases, of which (GaP)x(Si2)1-x,0<x<l is an example. Substitution of B-N (or Ga-P) by C-C (or Si-Si) atom pairs at lattice sites is characteristic of these solid solutions.

APA, Harvard, Vancouver, ISO, and other styles

10

Kononenko, Vitali V., Maxim S. Komlenok, Pavel A. Chizhov, Vladimir V. Bukin, Vladislava V. Bulgakova, Andrey A. Khomich, Andrey P. Bolshakov, Vitaly I. Konov, and Sergey V. Garnov. "Efficiency of Photoconductive Terahertz Generation in Nitrogen-Doped Diamonds." Photonics 9, no. 1 (December 29, 2021): 18. http://dx.doi.org/10.3390/photonics9010018.

Full text

Abstract:

The efficiency of the generation of terahertz radiation from nitrogen-doped (∼0.1–100 ppm) diamonds was investigated. The synthetic polycrystalline and monocrystalline diamond substrates were pumped by a 400 nm femtosecond laser and tested for the photoconductive emitter operation. The dependency of the emitted THz power on the intensity of the optical excitation was measured. The nitrogen concentrations of the diamonds involved were measured from the optical absorbance, which was found to crucially depend on the synthesis technique. The observed correlation between the doping level and the level of the performance of diamond-based antennas demonstrates the prospects of doped diamond as a material for highly efficient large-aperture photoconductive antennas.

APA, Harvard, Vancouver, ISO, and other styles

11

Ruoff, Arthur L., Samuel T. Weir, Keith E. Brister, and Yogesh K. Vohra. "Synthetic diamonds produce pressure of 125 GPa (1.25 Mbar)." Journal of Materials Research 2, no. 5 (October 1987): 614–18. http://dx.doi.org/10.1557/jmr.1987.0614.

Full text

Abstract:

Synthetic gray-blue diamonds were used as anvils in a diamond anvil cell to produce a pressure of 125 GPa (1.25 Mbar) in a gasketed sample. Pressure was measured by x-ray diffraction methods by using gold and iron as a calibrant and also by optical methods based on the shift of the fluorescence peaks of ruby with pressure. The future potential of synthetic diamonds for ultrapressure research is discussed.

APA, Harvard, Vancouver, ISO, and other styles

12

Lavrinenko, V., V. Poltoratskyi, О. Pasichnyi, V. Solod, and D. Muzichka. "MODIFICATION OF HEAT-RESISTANT OXIDES AND CHLORIDES OF GRAIN SURFACES OF SYNTHETIC DIAMOND GRINDING POWDERS FOR APPLICATION IN GRINDING TOOLS." Collection of scholarly papers of Dniprovsk State Technical University (Technical Sciences) 2, no. 39 (December 21, 2021): 51–58. http://dx.doi.org/10.31319/2519-2884.39.2021.6.

Full text

Abstract:

Further development of modern technologies of diamond processing is connected with application in the diamond tool of powders with new unique properties, special morphology of grains, with the increased chemical and thermal stability. To increase the heat resistance of diamonds, they are covered with a metal (metallization) or glass-ceramic layer, or introduced into the reaction mixture used in the synthesis of diamonds, alloying additives of certain elements. Recently, other methods of coating to increase the heat resistance of diamonds have been developed, such as: vacuum ion-plasma sputtering, epitaxial synthesis, magnetron sputtering, the method of liquid-phase deposition. The latter method is promising for modifying the grain surface of grinding powders of superhard materials by heat-resistant inorganic non-metallic coatings, as it is the most economically advantageous. Determining the features of the technology of modification by the method of liquid-phase application of heat-resistant inorganic coatings (oxides and chlorides of metals and nonmetals) on the surface of grains of grinding powders of synthetic diamond brand AC6, used for grinding tools in mechanical engineering. Modification was performed by the isothermal method of liquid-phase application of saturated solutions of both heat-resistant oxides (В2О3, Al2O3), chlorides (СаСl2, NaCl, MgCl2, FeCl3), and their mixtures (В2О3+СаСl2, В2О3+NaCl). Based on the analysis of the results of the research, it can be stated that the application of coatings of inorganic substances (some oxides and chlorides) increases the heat resistance of synthetic diamond grinding powders. Modification allows to reduce expenses of diamonds in wheels at grinding. Conditions for modification of heat-resistant oxides and chlorides, as well as their mixtures, grain surface of synthetic diamond grinding powders are determined. Modification of the surface of diamond grains with a combination of B2O3+Al2O3 is guaranteed to double the wear resistance of diamond wheels. It is established that in all cases of modification the roughness of the parameter Ra decreases. It is determined that by changing the surface modifier of diamond grains it is possible to affect the bearing capacity of the rough surface obtained by grinding. The development of effective ways to increase the heat resistance of grinding powders made of superhard materials, primarily abrasive grinding powders made of synthetic diamond powders, helps to improve the quality of the grinding tool.

APA, Harvard, Vancouver, ISO, and other styles

13

Zhdanov, Vladislav, Marina Sokolova, Pavel Smirnov, Lukasz Andrzejewski, Julia Bondareva, and Stanislav Evlashin. "A Comparative Analysis of Energy and Water Consumption of Mined versus Synthetic Diamonds." Energies 14, no. 21 (October 28, 2021): 7062. http://dx.doi.org/10.3390/en14217062.

Full text

Abstract:

In our research, we analyzed the energy and water consumption in diamond mining and laboratory synthesis operations. We used publicly available reports issued by two market leaders, DeBeers and ALROSA, to estimate water and energy use per carat of a rough diamond. The efficiency of the two most popular synthesis technologies for artificial diamonds—High-Pressure-High-Temperature (HPHT) and Microwave-assisted Chemical Vapor Deposition (M-CVD)—was examined. We found that the modern HPHT presses, with open cooling circuits, consume about 36 kWh/ct when producing gem-quality and average-sized (near-) colorless diamonds. ALROSA and DeBeers use about 96 kWh/ct and 150 kWh/ct, respectively, including all energy required to mine. Energy consumption of M-CVD processes can be different and depends on technological conditions. Our M-CVD machine is the least energy-efficient, requiring about 215 kWh/ct in the single-crystal regime, using 2.45-GHz magnetron for the support synthesis. The M-CVD methods of individual synthetic companies IIa Technology and Ekati Mine are different from our results and equal 77 and 143 kWh/ct, respectively. Water consumption for the HPHT and M-CVD methods was insignificant: approximately zero and 0.002 m3/ct, respectively, and below 0.077 m3/ct for ALROSA-mined diamonds. This study touches upon the impact of the diamond production methods used on the carbon footprint.

APA, Harvard, Vancouver, ISO, and other styles

14

Calvão, Filipe, and Lindsay Bell. "From Ashes to Diamonds." TSANTSA – Journal of the Swiss Anthropological Association 26 (June 30, 2021): 122–38. http://dx.doi.org/10.36950/tsantsa.2021.26.6916.

Full text

Abstract:

This article examines the making and makers of “memorial diamonds.” These are “natural” diamonds identical to gemstones found in nature but produced in laboratories with carbon sourced from genetic material (cremation ashes) or other objects of symbolic and emotional value. Threading corporality and objectified life forms, we examine the transformation from ashes to the “afterlife” of these “living” objects that are at once synthetic and organic. We ask, first, what material and affective properties distinguish synthetic diamonds from those extracted from nature? Second, how are these living and memorialized representations of inert substances – in continuity with bodily elements of the deceased – valued and mediated through “real” human, though artificially grown, natural objects? Drawing from research with the leading companies in the memorial diamond business in Switzerland and the United States, this article suggests that these diamonds’ singular connection to the human body offer a window into the transmutations between nature and the artificial, memory and material likeness, life and death.

APA, Harvard, Vancouver, ISO, and other styles

15

McManus, Catherine E., Nancy J. McMillan, James Dowe, and Julie Bell. "Diamonds Certify Themselves: Multivariate Statistical Provenance Analysis." Minerals 10, no. 10 (October 16, 2020): 916. http://dx.doi.org/10.3390/min10100916.

Full text

Abstract:

The country or mine of origin is an important economic and societal issue inherent in the diamond industry. Consumers increasingly want to know the provenance of their diamonds to ensure their purchase does not support inhumane working conditions. Governments around the world reduce the flow of conflict diamonds via paper certificates through the Kimberley Process, a United Nations mandate. However, certificates can be subject to fraud and do not provide a failsafe solution to stopping the flow of illicit diamonds. A solution tied to the diamonds themselves that can withstand the cutting and manufacturing process is required. Here, we show that multivariate analysis of LIBS (laser-induced breakdown spectroscopy) diamond spectra predicts the mine of origin at greater than 95% accuracy, distinguishes between natural and synthetic stones, and distinguishes between synthetic stones manufactured in different laboratories by different methods. Two types of spectral features, elemental emission peaks and emission clusters from C-N and C-C molecules, are significant in the analysis, indicating that the provenance signal is contained in the carbon structure itself rather than in inclusions.

APA, Harvard, Vancouver, ISO, and other styles

16

KVASNYTSYA, V. M. "About Diamonds of the Ingul-Ingulets Domain (the Ukrainian Shield)." Mineralogical Journal 43, no. 1 (2021): 87–96. http://dx.doi.org/10.15407/mineraljournal.43.01.087.

Full text

Abstract:

Three finds of diamonds on the Ingul-Ingulets domain of the Ukrainian Shield are considered: in breccia-like rocks of the Gruzke area, in eclogite-like rocks in the basin of the Ingul River and the Zeleny Gayi meteorite crater. A brief description of these diamonds is made, which represent their different geological and genetic types. Тhe veracity of these diamond findings and the origin of their crystals are appreciated. It is shown that 8 diamonds of the Gruzke area differ in size (0.2-1.4 mm), shape, colour, set of nitrogen centres and degree of preservation. According to infrared spectroscopy, all the studied crystals can be attributed to natural diamonds of the mantle type and distinguish them into separate groups, as they belong to several spectral types: IIa, IaAB, Iab and Ib. However, there are several doubts about the veracity of this finding: 1. Finding in small samples of the core wells of such a high concentration of diamonds. 2. A large variety of crystals in these samples by spectral types of physical classification. 3. Signs of mechanical wear on all crystals, which does not exclude the version of their origin from a diamond drill bit (a mixture of crystals of the natural and possibly synthetic diamond). The question of whether the found diamonds belong to the breccia-like rocks of the Gruzke area remains open. Small diamonds (up to 0.3 mm), which are found in eclogite-like rocks in the basin of the Ingul River on several grounds (mainly cubo-octahedral habit, manifestations of skeletal forms of growth, flat surface of the cube faces, yellow-green colour, inclusions) are very similar to crystals of synthetic HPHT diamond. However, the same small diamonds are found in the rocks of the Euro-Asian Alpine and the Ural and Central-Asian Caledonian ophiolite belts and the eruptions of modern volcanoes in Kamchatka. Such diamonds are also found in lamproite-like rocks of the Mriya pipe in the Azov Sea region, and they are found in weathering crusts and terrigenous deposits of Ukraine. It is necessary to find out the true nature of these findings. Therefore, it is necessary to audit all finds of such diamonds in Ukraine. It is shown that diamonds from the Zeleny Gayi meteorite crater are typical impact apographitic crystals - diamond paramorphoses on graphite. The conclusions of some researchers about the mantle nature of these diamonds from this crater are denied.

APA, Harvard, Vancouver, ISO, and other styles

17

Guignard, Jérémy, Mythili Prakasam, and Alain Largeteau. "A Review of Binderless Polycrystalline Diamonds: Focus on the High-Pressure–High-Temperature Sintering Process." Materials 15, no. 6 (March 16, 2022): 2198. http://dx.doi.org/10.3390/ma15062198.

Full text

Abstract:

Nowadays, synthetic diamonds are easy to fabricate industrially, and a wide range of methods were developed during the last century. Among them, the high-pressure–high-temperature (HP–HT) process is the most used to prepare diamond compacts for cutting or drilling applications. However, these diamond compacts contain binder, limiting their mechanical and optical properties and their substantial uses. Binderless diamond compacts were synthesized more recently, and important developments were made to optimize the P–T conditions of sintering. Resulting sintered compacts had mechanical and optical properties at least equivalent to that of natural single crystal and higher than that of binder-containing sintered compacts, offering a huge potential market. However, pressure–temperature (P–T) conditions to sinter such bodies remain too high for an industrial transfer, making this the next challenge to be accomplished. This review gives an overview of natural diamond formation and the main experimental techniques that are used to synthesize and/or sinter diamond powders and compact objects. The focus of this review is the HP–HT process, especially for the synthesis and sintering of binderless diamonds. P–T conditions of the formation and exceptional properties of such objects are discussed and compared with classic binder-diamonds objects and with natural single-crystal diamonds. Finally, the question of an industrial transfer is asked and outlooks related to this are proposed.

APA, Harvard, Vancouver, ISO, and other styles

18

Karpovich, Z. A., E. I. Zhimulev, and A. I. Chepurov. "Growth Diamond on an Impact Lonsdaleite-bearing Diamond from the Popigai Astrobleme." Bulletin of Irkutsk State University. Series Earth Sciences 38 (2021): 41–53. http://dx.doi.org/10.26516/2073-3402.2021.38.41.

Full text

Abstract:

The Popigai astrobleme contains huge reserves of diamonds with unusual properties. In impact diamonds from the Popigai astrobleme, the cubic phase and lonsdaleite are intergrown. In order to study the relationship of lonsdaleite-bearing impact diamonds with diamond, an experimental study of the features of diamond growth on lonsdaleite-bearing fragments was carried out. The experiments were carried out on a high-pressure apparatus of the “BARS” type at 5.5 GPa and 1450 ° C in the Fe-Ni-C system (nickel 36 wt.%). Impact Popigai diamonds were used as seed crystals. As a result of the study, it was found that the newly formed crystals are represented by a cubic phase, while the lonsdaleite in the seed crystals was preserved and the lonsdaleite / diamond ratio did not change. The newly formed cubic diamond in its main properties (Raman spectra, morphology, color, etc.) corresponds to synthetic diamonds grown in the iron-nickel system. The difference between the growth of crystals on seeds of impact diamonds and growth on a single-crystal seed of diamond was that the nucleation of crystals began from different points of the seed of the impact diamond. Multi-headed growth was observed and, as a result, an intergrowth of diamond crystals was formed. Probably, the initial misorientation of the points of nucleation of subindividuals leads to multi-headed growth of crystals in an intergrowth, in contrast to single-crystal growth of diamond on a single- crystal seed.

APA, Harvard, Vancouver, ISO, and other styles

19

Tsysar, Maksym, Sergey Ivakhnenko, Anatoliy Zakora, Galina Ilnitska, Oleg Zanevsky, and Eugenia Zakora. "Dependence of static strength of large single crystals of synthetic diamond type and Ib octahedral habit after heat treatment on their size." Mechanics and Advanced Technologies 5, no. 2 (November 9, 2021): 177–82. http://dx.doi.org/10.20535/2521-1943.2021.5.2.233077.

Full text

Abstract:

This article focuses on the problem of using large single crystals of type Ib synthetic diamond in single crystal and drilling tools. According to the literature review for the use of large diamonds in drilling equipment relevant conditions. The is shown possible negative effects of the temperature load on the diamond single crystal. The is presented developed technique for estimating the static strength of large diamond single crystals. It has been shown that microcrystals in the form of octahedra and cubes are formed as a result of heat treatment on the surface of synthetic diamond single crystals. The results of studies of the strength of large single crystals of synthetic diamonds of millimeter size are shown. In contrast to the classical approach, when IIb crystals are used for the production of drilling equipment, we present Ib crystals because they are closer to natural diamond in terms of physical and mechanical properties. The static strength criterion was used to assess the strength. It has been shown that crystals with a size of 1000 ... 1100 μm have a higher value of static strength than crystals with a size of 1200 μm and larger.

APA, Harvard, Vancouver, ISO, and other styles

20

Iverson, Jan. "Transparency and Synthetic Diamonds." Gems & Gemology 48, no. 2 (July 1, 2012): 79. http://dx.doi.org/10.5741/gems.48.2.79.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Shulshenko, A. A., L. Varga, and B. Hidasi. "Inclusions of synthetic diamonds." International Journal of Refractory Metals and Hard Materials 12, no. 6 (January 1993): 349–55. http://dx.doi.org/10.1016/0263-4368(93)90025-b.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Senyut, V. T. "Sintering of composite materials for tool appointment, based on impact diamonds, under high pressure and temperatures." Proceedings of the National Academy of Sciences of Belarus, Physical-Technical Series 66, no. 1 (April 2, 2021): 47–57. http://dx.doi.org/10.29235/1561-8358-2021-66-1-47-57.

Full text

Abstract:

The article presents the results of a study of composite materials based on diamond-lonsdaleite abrasive (DLA) and various binders (Fe–Ti mechanocomposite, silicon carbide SiC). A metal-matrix composite material with a multimodal nano- and microlevel structure, characterized by increased adhesion of diamond grains to the binder, is obtained on the basis of impact diamonds and a Fe–Ti nano-mechanical composite. It is shown that the use of impact diamonds in comparison with synthetic diamonds makes it possible to reduce the pressure of thermobaric treatment by 30–50 % at the same sintering temperatures. The use of Fe–Ti–DLA composites in the process of magnetic-abrasive polishing (MAP) makes it possible to increase the removal rate of material based on silicon by 1.5–2 times and reduce the processing time by 30 % compared to ferroabrasive powder (FAP) based on synthetic diamonds. The effect of adding of silicon carbide on the process of obtaining a superhard composite material impact diamond – SiC is investigated. It is found that adding of SiC helps to reduce the defectiveness of the material and increase the homogeneity of its structure in comparison with the material without adding of a binder. In this case, an increase in the content of SiC and Si also leads to an inversion of the structure type of the superhard composite from polycrystalline to matrix. It is found that the additional use of amorphous soot and boron affects the refinement of the matrix structure of the composite material due to the formation of boron carbide and secondary finely dispersed silicon carbide.

APA, Harvard, Vancouver, ISO, and other styles

23

Sumiya, H., and T. Irifune. "Hardness and deformation microstructures of nano-polycrystalline diamonds synthesized from various carbons under high pressure and high temperature." Journal of Materials Research 22, no. 8 (August 2007): 2345–51. http://dx.doi.org/10.1557/jmr.2007.0295.

Full text

Abstract:

Mechanical properties of high-purity nano-polycrystalline diamonds synthesized by direct conversion from graphite and various non-graphitic carbons under static high pressures and high temperatures were investigated by microindentation testing with a Knoop indenter and observation of microstructures around the indentations. Results of indentation hardness tests using a superhard synthetic diamond Knoop indenter showed that the polycrystalline diamond synthesized from graphite at ⩾15 GPa and 2300–2500 °C (consisting of fine grains 10–30 nm in size and layered crystals) has very high Knoop hardness (Hk ⩾ 110 GPa), whereas the hardness of polycrystalline diamonds synthesized from non-graphitic carbons at ⩾15 GPa and below 2000 °C (consisting only of single-nano grains 5–10 nm in size) are significantly lower (Hk = 70 to 90 GPa). Microstructure observations beneath the indentations of these nano-polycrystalline diamonds suggest that the existence of a lamellar structure and the bonding strength of the grain boundary play important roles in controlling the hardness of the polycrystalline diamond.

APA, Harvard, Vancouver, ISO, and other styles

24

Jaskie, James E. "Diamond-Based Field-Emission Displays." MRS Bulletin 21, no. 3 (March 1996): 59–64. http://dx.doi.org/10.1557/s0883769400036149.

Full text

Abstract:

Diamond has existed in the natural state for thousands of years. It was mainly used as a jewel for its optical brilliance and for its hardness. In the 1950s methods were developed to fabricate synthetic diamonds commercially. This greatly increased diamond's industrial use, mostly for grinding and lapping applications. Diamond is a crystalline form of carbon, a group-IV element in the periodic table. Silicon and germanium are also Group-IV elements and also have the same crystalline lattice structure as diamond. Hence there has been theoretical interest in diamond's electronic properties since the beginning of the semiconductor age. However the cost and poor crystalline quality of both natural and synthetic diamond have precluded any real industrial interest in diamond as an electronic material. Methods of low-temperature and low-pressure diamond-film deposition, developed initially by the Russians in the 1950s and 1960s (and thence by the Japanese, and eventually by others) has made it possible to use this exotic material as an electronic substrate.Diamond, in single-crystalline, polycrystalline, and diamondlike carbon (DLC) forms, is a material with many unusual properties. It is the hardest naturally occurring material, the most thermally conductive, and the most transparent. It also has the slickness of Teflon. In regard to many physical properties, it is at the extreme end of the scale. One of the more unusual and important properties that it possesses is its presentation of a rather small barrier to the emission of electrons into a vacuum.

APA, Harvard, Vancouver, ISO, and other styles

25

Gong, Jian Hong, Shu Xia Lin, and Jun Gao. "TEM and DSC Studies on the Synthetic Diamond Grown from Fe-Ni-C-B System under HPHT." Advanced Materials Research 320 (August 2011): 3–7. http://dx.doi.org/10.4028/www.scientific.net/amr.320.3.

Full text

Abstract:

Transmission Electron Microscope (TEM) and Different Scanning Calorimetry (DSC) Methods Were Used to Investigate the Diamonds Grown with Different Boron Content Alloy Catalysts under High-Pressure High-Temperature (HPHT). Experimental Results Demonstrated the Microstructure and Composition of Boride Compounds in Synthetic Diamond, such as (FeNi)23(CB)6 ,(Fe, Ni)3(C,B), (Fe,Ni)B and B4C, Whose Formation Process Was Analyzed. the Thermal Stability of Diamond Depends on Boron Concentration in Catalyst According to DSC Studies. we Analyzed the Reason of Diamond Oxidation.The Work Offers Valuable Information for Improving the Thermal Stability of Synthetic Diamond Crystals by Adjusting Boron Content in the Fe-Ni Based Catalyst.

APA, Harvard, Vancouver, ISO, and other styles

26

Pennisi, E. "Fullerene Helps Synthetic Diamonds Grow." Science News 140, no. 20 (November 16, 1991): 310. http://dx.doi.org/10.2307/3975801.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Boyajian, William E. "Tomorrow's Challenge: CVD Synthetic Diamonds." Gems & Gemology 39, no. 4 (January 1, 2003): 267. http://dx.doi.org/10.5741/gems.39.4.267.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Breeding, Christopher M., James E. Shigley, and Andy H. Shen. "As-grown, green synthetic diamonds." Journal of Gemmology 29, no. 7 (2005): 387–94. http://dx.doi.org/10.15506/jog.2005.29.7.387.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Su, Li-Xia, Chun-Xiang Zhao, Qing Lou, Chun-Yao Niu, Chao Fang, Zhen Li, Cheng-Long Shen, Jin-Hao Zang, Xiao-Peng Jia, and Chong-Xin Shan. "Efficient phosphorescence from synthetic diamonds." Carbon 130 (April 2018): 384–89. http://dx.doi.org/10.1016/j.carbon.2018.01.039.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Stockton, Carol M. "Consumer Research on Synthetic Diamonds." Journal of Gemmology 37, no. 6 (2021): 556. http://dx.doi.org/10.15506/jog.2021.37.6.556b.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Wang, Wuyi, Matthew S. Hall, Kyaw Soe Moe, Joshua Tower, and Thomas M. Moses. "Latest-Generation CVD-Grown Synthetic Diamonds From Apollo Diamond Inc." Gems & Gemology 43, no. 4 (January 1, 2007): 294–312. http://dx.doi.org/10.5741/gems.43.4.294.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Ruoff, A. L., and Y. K. Vohra. "Synthetic diamonds for multimegabar pressures in the diamond anvil cell." High Pressure Research 5, no. 1-6 (April 1990): 791–93. http://dx.doi.org/10.1080/08957959008246260.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Fang, Chao, Yuewen Zhang, Zhuangfei Zhang, Chongxin Shan, Weixia Shen, and Xiaopeng Jia. "Preparation of “natural” diamonds by HPHT annealing of synthetic diamonds." CrystEngComm 20, no. 4 (2018): 505–11. http://dx.doi.org/10.1039/c7ce02013a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Cheng, Dong Kai, Hong Qiu Ma, Dan Cao, and Fu Chang Ding. "Effect of FeNi30 Powder Catalyst by Water Atomizing on Synthesis High-Grade Diamond." Materials Science Forum 534-536 (January 2007): 41–44. http://dx.doi.org/10.4028/www.scientific.net/msf.534-536.41.

Full text

Abstract:

This paper described the preparation method for composing high-grade synthetic diamond by water atomizing using FeNi30 powder catalyst.The FeNi30 powder was corroded by the 100Mpa super high-pressure water atomizing technique and selecting organic RY corrosion inhibitor. Contrast test of the original FeNi30 powder and the treated FeNi30 powder on synthetic diamonds were conducted under super high-temperature and high-pressure using cubic press. The result shows that after the FeNi30 powder was corroded,the FeO phase and Fe3O4 phase could not longer be found by X-Ray analysis.Furthermore,the oxygen content of the powder increased up to 100PPM under the natural condition for one year. After the powder was mixed with graphite powder, diamond could be made by isostatic pressing method. Its color became darker and its TTI value increased slightly. However, its penetrability was still different from the high-grade synthetic diamond made by gas atomizing FeNi30 powder catalyst.

APA, Harvard, Vancouver, ISO, and other styles

35

Олейничук, Е. А., П. А. Данилов, В. Н. Леднев, П. А. Сдвиженский, М. С. Кузнецов, С. А. Тарелкин, М. Г. Бондаренко, and Р. А. Хмельницкий. "Лазерно-индуцированная люминесценция синтетического алмаза, легированного бором, при различной длительности лазерного импульса." Оптика и спектроскопия 130, no. 4 (2022): 477. http://dx.doi.org/10.21883/os.2022.04.52258.47-21.

Full text

Abstract:

Excitation of type IIb synthetic diamond by ultrashort laser pulses in the visible range causes broadband luminescence in the UV visible range; the observed luminescence band can be attributed to the A band characteristic of diamonds. The photoluminescence spectra were obtained at different laser pulse durations (0.3–6.2 ps) depending on the pulse energy. A nonlinear dependence of the luminescence yield on the intensity of ultrashort pulses is established.

APA, Harvard, Vancouver, ISO, and other styles

36

Wang, Wuyi, Ulrika F. S. D'Haenens-Johansson, Paul Johnson, Kyaw Soe Moe, Erica Emerson, Mark E. Newton, and Thomas M. Moses. "CVD Synthetic Diamonds from Gemesis Corp." Gems & Gemology 48, no. 2 (July 1, 2012): 80–97. http://dx.doi.org/10.5741/gems.48.2.80.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Lu, Taijin, Jie Ke, Yan Lan, Zhonghua Song, Jian Zhang, Shi Tang, Jun Su, Huiru Dai, and Xuxu Wu. "Current Status of Chinese Synthetic Diamonds." Journal of Gemmology 36, no. 8 (2019): 748–57. http://dx.doi.org/10.15506/jog.2019.36.8.748.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Collins, A. T., M. Stanley, and G. S. Woods. "Nitrogen isotope effects in synthetic diamonds." Journal of Physics D: Applied Physics 20, no. 7 (July 14, 1987): 969–74. http://dx.doi.org/10.1088/0022-3727/20/7/022.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Taldenkov, A. N., A. V. Inyushkin, E. A. Chistotina, V. G. Ralchenko, A. P. Bolshakov, and E. N. Mokhov. "Magnetic properties of the natural and isotope-modified diamond and silicon carbide." EPJ Web of Conferences 185 (2018): 04007. http://dx.doi.org/10.1051/epjconf/201818504007.

Full text

Abstract:

The magnetic properties of single crystals of synthetic diamond and crystals of silicon carbide were studied. High-purity samples of diamonds synthesized with HPHT and CVD technologies were used. The crystals of silicon carbide were grown by sublimation and industrial technology. Along with samples with a natural isotopic composition, monoisotopic crystals of diamond (99.96% 12C and 99.96% 13C) and silicon carbide (99.993% of 28Si) were studied. On the basis of the data obtained, the diamagnetic susceptibility was determined and the concentration of paramagnetic centers and the content of the ferromagnetic component were evaluated. The results are discussed.

APA, Harvard, Vancouver, ISO, and other styles

40

Лебедев, В. Ф., Д. В. Булыга, and А. В. Колядин. "Анализ примесного состава синтетических HPHT-алмазов методом лазерно-искровой эмиссионной спектроскопии в условиях лазерно-индуцированной модификации поверхности." Письма в журнал технической физики 46, no. 9 (2020): 7. http://dx.doi.org/10.21883/pjtf.2020.09.49363.18164.

Full text

Abstract:

Analysis of impurities in multisectoral plates of boron- and nitrogen-doped synthetic HPHT diamonds was performed by laser-induced breakdown spectroscopy. It was shown that comparative analysis of plasma emission bands during laser-induced graphitization process is effective approach to distinguishing types of diamonds and crystallographic orientations of sectors.

APA, Harvard, Vancouver, ISO, and other styles

41

Sokolov, Evgeny G., Vladimir P. Artemiev, and Alexander V. Ozolin. "OBTAINING DIAMOND-METAL COMPOSITES BY MEANS OF BRAZES CONTAINING REFRACTORY FILLERS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 59, no. 8 (July 17, 2018): 56. http://dx.doi.org/10.6060/tcct.20165908.20y.

Full text

Abstract:

The interaction of Sn-Cu-Co-W brazes containing cobalt and tungsten powder as refractory fillers with the synthetic diamonds AS150 is studied. It was found, that addition into braze the cobalt powder provides the wetting of diamonds at brazing and their strong fixation in metal matrix of composite.

APA, Harvard, Vancouver, ISO, and other styles

42

Wang, Z. L., J. Bentley, R. E. Clausing, L. Heatherly, and L. L. Horton. "Reflection electron microscopy of as-grown diamond surfaces." Proceedings, annual meeting, Electron Microscopy Society of America 51 (August 1, 1993): 1006–7. http://dx.doi.org/10.1017/s0424820100150861.

Full text

Abstract:

It has been found that the abrasion of diamond-on-diamond depends on the crystal orientation. For a {100} face, the friction coefficient for sliding along <011> is much higher than that along <001>. For a {111} face, the abrasion along <11> is different from that in the reverse direction <>. To interpret these effects, a microcleavage mechanism was proposed in which the {100} and {111} surfaces were assumed to be composed of square-based pyramids and trigonal protrusions, respectively. Reflection electron microscopy (REM) has been applied to image the microstructures of these diamond surfaces.{111} surfaces of synthetic diamond:The synthetic diamonds used in this study were obtained from the De Beers Company. They are in the as-grown condition with grain sizes of 0.5-1 mm without chemical treatment or mechanical polishing. By selecting a strong reflected beam in the reflection high-energy electron diffraction (RHEED) pattern, the dark-field REM image of the surface is formed (Fig. 1).

APA, Harvard, Vancouver, ISO, and other styles

43

Song, Zhonghua, Huiru Dai, Bo Gao, and Wenfang Zhu. "Identification of Pink-Coloured CVD Synthetic Diamonds from Huzhou Sino-C Semiconductor Co. in China." Crystals 11, no. 8 (July 27, 2021): 872. http://dx.doi.org/10.3390/cryst11080872.

Full text

Abstract:

In recent years, increasing numbers of pink-coloured CVD synthetic diamonds have appeared on the market. One of the major sources is Huzhou SinoC Semiconductor Science and Technology Co., Ltd., Zhejiang province of China. In this article, seven pink-coloured CVD-grown diamonds produced in the last two years by Huzhou have been investigated and identified, including their gemological and spectroscopic characteristics. In DiamondView, they fluoresced orange–red, with an obscure striated growth structure, which is common for CVD synthetics. The mid-IR absorption spectra of these samples showed some single nitrogen and hydrogen-related features (1130, 1344, 3123, 3323 cm−1), which indicated that the diamonds were type Ib and were CVD-grown diamonds. The H1a defect annealed out at approximately 1400 °C, whereas the 3107 cm−1 defect was produced by annealing above 1700 or 1800 °C. This implied that the samples had undergone two separate heat treatments: first, a high-temperature anneal (possibly an HPHT treatment to reduce any brown colour), which would have produced the 3107 cm−1 defects and a small number of A centres, followed by irradiation, followed by annealing above 800 °C to make the vacancies mobile. The UV–Vis–NIR absorption spectra showed distinct NV-related features (575 and 637 nm), the main reason for the pink colour. Photoluminescence spectra obtained at liquid nitrogen temperature recorded radiation-related emissions (388.9, 503.5 nm), a strong N-V centre, H3 and H2 defects, and many unassigned emissions. These pink CVD products can be separated from natural and treated pink-coloured diamonds by a combination of optical spectroscopic properties, such as fluorescence colour, and absorption features in the infrared and UV–Vis regions.

APA, Harvard, Vancouver, ISO, and other styles

44

Gucsik, Arnold, Hirotsugu Nishido, Kiyotaka Ninagawa, Ulrich Ott, Akira Tsuchiyama, Masahiro Kayama, Irakli Simonia, and Jean-Paul Boudou. "Cathodoluminescence Microscopy and Spectroscopy of Micro- and Nanodiamonds: An Implication for Laboratory Astrophysics." Microscopy and Microanalysis 18, no. 6 (December 2012): 1285–91. http://dx.doi.org/10.1017/s143192761201330x.

Full text

Abstract:

AbstractColor centers in selected micro- and nanodiamond samples were investigated by cathodoluminescence (CL) microscopy and spectroscopy at 298 K [room temperature (RT)] and 77 K [liquid-nitrogen temperature (LNT)] to assess the value of the technique for astrophysics. Nanodiamonds from meteorites were compared with synthetic diamonds made with different processes involving distinct synthesis mechanisms (chemical vapor deposition, static high pressure high temperature, detonation). A CL emission peak centered at around 540 nm at 77 K was observed in almost all of the selected diamond samples and is assigned to the dislocation defect with nitrogen atoms. Additional peaks were identified at 387 and 452 nm, which are related to the vacancy defect. In general, peak intensity at LNT at the samples was increased in comparison to RT. The results indicate a clear temperature—dependence of the spectroscopic properties of diamond. This suggests the method is a useful tool in laboratory astrophysics.

APA, Harvard, Vancouver, ISO, and other styles

45

Takaba, Hiroyuki, Koji Kusafuka, Mikka Nishitani-Gamo, Yoichiro Sato, Toshihiro Ando, Jun Kubota, Akihide Wada, and Chiaki Hirose. "Vibrational sum-frequency observation of synthetic diamonds." Diamond and Related Materials 10, no. 9-10 (September 2001): 1643–46. http://dx.doi.org/10.1016/s0925-9635(01)00447-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Laptev, V. A., S. M. Pimenov, and G. A. Shafeev. "Laser-assisted nickel deposition onto synthetic diamonds." Thin Solid Films 241, no. 1-2 (April 1994): 76–79. http://dx.doi.org/10.1016/0040-6090(94)90400-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Skury, A. L. D., G. S. Bobrovnitchii, S. N. Monteiro, and C. C. Gomes. "Recovery of synthetic diamonds from scrapped sawblades." Separation and Purification Technology 35, no. 3 (March 2004): 185–90. http://dx.doi.org/10.1016/s1383-5866(03)00138-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Rakin, V. I., and N. N. Piskunova. "Micro-, macro-, and nanomorphology of synthetic diamonds." Doklady Earth Sciences 455, no. 2 (April 2014): 450–53. http://dx.doi.org/10.1134/s1028334x14050109.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Pal'yanov, Yu N., Yu M. Borzdov, V. A. Gusev, A. G. Sokol, A. F. Khokhryakov, G. M. Rylov, V. A. Chernov, and I. N. Kupriyanov. "High-quality synthetic diamonds for SR application." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 448, no. 1-2 (June 2000): 179–83. http://dx.doi.org/10.1016/s0168-9002(99)00749-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Shigley, James E., Thomas M. Moses, Ilene Reinitz, Shane Elen, Shane F. McClure, and Emmanuel Fritsch. "Gemological Properties of Near-Colorless Synthetic Diamonds." Gems & Gemology 33, no. 1 (April 1, 1997): 42–53. http://dx.doi.org/10.5741/gems.33.1.42.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!