Synthetic diamond

From Wikipedia, the free encyclopedia

Jump to: navigation, search
Synthetic diamonds of various colors grown by the high-pressure high-temperature technique

Synthetic diamond (also known as HPHT diamond or CVD diamond depending on the production process used) is diamond produced in a technological process, as opposed to natural diamond, which is produced by geological processes.

Numerous individual attempts to grow synthetic diamond were documented between 1879 and 1928, but none of them have been confirmed to have produced diamonds. In the 1940–1950s, systematic research began in the United States, Sweden and the Soviet Union to grow diamond using chemical vapor deposition (CVD) and high-pressure high-temperature (HPHT) processes. The first reproducible synthesis was reported around 1953. Those two processes still dominate production of synthetic diamond. A third method, known as detonation synthesis, has recently entered the diamond market. In this process, nanometer-sized diamond grains are created in an explosion of carbon-containing explosives. A fourth diamond synthesis variety, using high-power ultrasonic treatment of graphite, has been demonstrated in the laboratory, but has no commercial use yet.

The properties of synthetic diamond depend on the details of the manufacturing processes, and can be inferior or superior to those of natural diamond; in particular, the hardness, thermal conductivity and electron mobility are superior in some synthetic diamonds (either HPHT or CVD). Consequently, synthetic diamond is widely used in abrasives, cutting and polishing tools and in heat sinks. Its applications as a material of active electronic devices, including high-power switches at power stations, high-frequency field-effect transistors and light-emitting diodes are being developed. Detectors of ultraviolet (UV) light or high-energy particles, made of synthetic diamond, are already used at high-energy research facilities and are available commercially. Because of its unique combination of thermal and chemical stability, low thermal expansion and high optical transparency in a wide spectral range, synthetic diamond is becoming the most popular material for optical windows in high-power CO2 lasers and gyrotrons.

Both CVD and HPHT diamonds can be cut into gems of various colors: clear white, yellow, brown, blue, green and orange. The appearance of synthetic gems on the market created major concerns in the diamond trading business, as a result of which special spectroscopic devices and techniques have been developed to distinguish synthetic and natural diamonds.

Contents

[edit] History

Experimental set-up of Willard Hershey

After the 1797 discovery that diamond was pure carbon, many attempts were made to convert various cheap forms of carbon into diamond—generally with little success. The earliest successes reported in the field were by James Ballantyne Hannay in 1879[1] and by Ferdinand Frédéric Henri Moissan in 1893. Their method involved heating charcoal at up to 3500 °C with iron in a carbon crucible in an electric furnace, in which an electric arc was struck between carbon rods inside blocks of lime.[2] The molten iron was then rapidly cooled by immersion in water. The contraction generated by the cooling supposedly produced the high pressure required to transform graphite into diamond. Moissan published his work in a series of articles in the 1890s.[3]

Many other scientists tried to replicate his experiments. Sir William Crookes claimed success in 1909. Otto Ruff claimed in 1917 to have reproduced diamonds up to 7 mm in diameter,[4] but later retracted his claims.[5] In 1926, Dr. Willard Hershey of McPherson College replicated Moissan's and Ruff's experiments, producing a synthetic diamond. That diamond is on display today at the McPherson Museum in Kansas.[6] Despite the claims of Moissan, Ruff, and Hershey, no other experimenter could reproduce their synthesis.[7][8]

The most definitive replication attempts were performed by Sir Charles Algernon Parsons. A prominent scientist and engineer, known for his invention of the steam turbine, he spent 30 years (1882–1922) and a considerable part of his fortune to reproduce the experiments of Moissan and Hannay but also adapted processes of his own. Parsons was known for his painstakingly accurate approach and methodical record keeping; all his resulting samples were preserved for further analysis by an independent party.[9] He wrote a number of articles—some of the earliest on HPHT diamond—in which he claimed to have produced small diamonds.[10] However in 1928 he authorized Dr. C.H. Desch to publish an article[11] in which he stated his belief that no synthetic diamonds (including those of Moissan and others) had been produced up to that date. He suggested that most diamonds that had been produced up to that point were likely synthetic spinel.[7]

[edit] GE diamond project

In 1941, an agreement was made between three companies—General Electric (GE), Norton and Carborundum—to further develop diamond synthesis. They were able to heat carbon to about 3000 °C under a pressure of 3.5 gigapascals (GPa) for a few seconds. The Second World War ended this project soon thereafter. It was resumed in 1951 at the Schenectady Laboratories of GE, and a high-pressure diamond group was formed with F.P. Bundy and H.M. Strong. Tracy Hall and others joined it shortly thereafter.[12]

The group improved on the anvils designed by Percy Bridgman, who received a Nobel prize for his work in 1946. Bundy and Strong made the first improvements and more were made later by Hall. The GE team used tungsten carbide anvils within a hydraulic press to squeeze the carbonaceous sample held in a catlinite container, the finished grit being squeezed out of the container through a gasket. The team recorded diamond synthesis on one occasion, but the experiment could not be reproduced because of uncertain synthesis conditions.[12]

A belt press produced in the 1980s by KOBELCO

Hall achieved the first commercially successful synthesis of diamond on December 16, 1954 (announced on February 15, 1955). His breakthrough was using a "belt" press, which was capable of producing pressures above 18 GPa and temperatures above 2400 °C. The "belt" press utilized a pyrophyllite container where graphite was dissolved within molten nickel, cobalt or iron, a "solvent-catalyst".[13] The largest diamond he produced was 0.15 mm across; it was too small and visually imperfect for jewelry, but usable in industrial abrasives. Hall's co-workers were able to replicate his work, and the discovery was published in the major journal Nature. He was the first person to grow a synthetic diamond with a reproducible, verifiable and well-documented process. He left GE in 1955, and three years later developed a new apparatus for the synthesis of diamond—a tetrahedral press with four anvils—to avoid infringing his previous patent, which was still assigned to GE.[9] Hall received a gold medal from the American Chemical Society in 1972 for his work in diamond synthesis.[12][14]

[edit] Later developments

Another successful diamond synthesis was achieved on February 16, 1953 in Stockholm, Sweden by the ASEA (Allmänna Svenska Elektriska Aktiebolaget), one of Sweden's major electrical manufacturing companies. Starting in 1949, ASEA employed a team of five scientists and engineers as part of a top-secret diamond-making project code-named QUINTUS. The team used a bulky split-sphere apparatus designed by Baltzar von Platen and Anders Kämpe.[12][15] Pressure was maintained within the device at an estimated 8.4 GPa for an hour. A few small diamonds were produced, but not of gem quality or size. The work was not reported until the 1980s.[9] During the 1980s a new competitor emerged in Korea, a company named Iljin Diamond; it was followed by hundreds of Chinese enterprises. Iljin Diamond allegedly accomplished diamond synthesis in 1988 by misappropriating trade secrets from GE via a Korean former GE employee.[16]

A scalpel with synthetic diamond blade

Synthetic gem-quality diamond crystals were first produced in 1970 (reported in 1971) by GE. The first successes used a pyrophyllite tube seeded at each end with thin pieces of diamond. The graphite feed material was placed in the center and the metal solvent (nickel) between the graphite and the seeds. The container was heated and the pressure was raised to about 5.5 GPa. The crystals grow as they flow from the center to the ends of the tube, and extending the length of the process produces larger crystals. Initially a week-long growth process produced gem-quality stones of around 5 mm (1 carat (200 mg)), and the process conditions had to be as stable as possible. The graphite feed was soon replaced by diamond grit because that allowed much better control of the shape of the final crystal.[9]

The first gem-quality stones were always yellow to brown in color due to contamination with nitrogen. Inclusions were common, especially "plate-like" ones from the nickel. Removing all nitrogen from the process by adding aluminum or titanium produced colorless "white" stones, and removing the nitrogen and adding boron produced blue ones.[17] However, removing nitrogen slowed the growth process and reduced the crystalline quality, so the process was normally run with nitrogen present. Although the GE stones and natural diamonds were chemically identical, their physical properties were not the same. The colorless stones produced strong fluorescence and phosphorescence under short-wavelength ultraviolet light, but were inert under long-wave UV. Among natural diamonds, only the rarer blue gems exhibit these properties. Contrary to natural diamonds, all the GE stones showed strong yellow fluorescence under X-rays.[9] The De Beers Diamond Research Laboratory has grown stones of up to 25 carats (5.0 g) for research purposes. Stable HPHT conditions were kept for 6 weeks to grow high-quality diamonds of this size. For economic reasons, the growth of most synthetic diamonds is terminated when they reach a weight of 1 carat (200 mg) to 1.5 carats (300 mg).[18]

In the 1950s, research started in the Soviet Union and the US on the growth of diamond by pyrolysis of hydrocarbon gases at the relatively low temperature of 800 °C. This low-pressure process is known as chemical vapor deposition (CVD). William G. Eversole reportedly achieved vapor deposition of diamond over diamond substrate in 1953, but it was not reported until 1962.[19] Diamond film deposition was independently reproduced by Angus and coworkers in 1968[20] and by Deryagin and Fedoseev in 1970.[21] Whereas Eversole and Angus used large, expensive, single-crystal diamonds as substrates, Deryagin and Fedoseev succeeded in making diamond films on non-diamond materials (silicon and metals), which led to massive research on inexpensive diamond coatings in the 1980s.[9]

[edit] Manufacturing technologies

There are several methods used to produce synthetic diamond. The original method uses high pressure and high temperature (HPHT) and is still widely used because of its relatively low cost. The process involves large presses that can weigh hundreds of tons to produce a pressure of 5 GPa at 1500 °C. The second method, using chemical vapor deposition (CVD), creates a carbon plasma over a substrate onto which the carbon atoms deposit to form diamond. Other methods include explosive formation (forming detonation nanodiamonds) and sonication of graphite solutions.[22][23][24]

[edit] High pressure, high temperature

Schematic of a belt press

In the HPHT method, there are three main press designs used to supply the pressure and temperature necessary to produce synthetic diamond: the belt press, the cubic press and the split-sphere (BARS) press.

The original GE invention by Tracy Hall uses the belt press wherein the upper and lower anvils supply the pressure load to a cylindrical inner cell. This internal pressure is confined radially by a belt of pre-stressed steel bands. The anvils also serve as electrodes providing electrical current to the compressed cell. A variation of the belt press uses hydraulic pressure, rather than steel belts, to confine the internal pressure.[25] Belt presses are still used today, but they are built on a much larger scale than those of the original design. [9]

The second type of press design is the cubic press. A cubic press has six anvils which provide pressure simultaneously onto all faces of a cube-shaped volume. The first multi-anvil press design was actually a tetrahedral press, using only four anvils to converge upon a tetrahedron-shaped volume.[26] The cubic press was created shortly thereafter to increase the volume to which pressure could be applied. A cubic press is typically smaller than a belt press and can more rapidly achieve the pressure and temperature necessary to create synthetic diamond. However, cubic presses cannot be easily scaled up to larger volumes: The pressurized volume can be increased by increasing the size of the anvils, but this also increases the amount of force needed on the anvils to achieve the same pressure. An alternative is to decrease the surface area to volume ratio of the pressurized volume, by using more anvils to converge upon a different platonic solid, such as a dodecahedron. However, such a press would be unnecessarily complex and difficult to manufacture.[27]

Schematic of a BARS system; the size of the outer barrel is reduced for presentation purposes

BARS is the most compact, efficient, and economical of all the diamond-producing presses. In the center of a BARS device, there is a ceramic cylindrical "synthesis capsule" of about 2 cm3 in size. The cell is placed into a cube of pressure-transmitting material (e.g., Pyrophyllite ceramics), which is pressed by inner anvils made from cemented carbide (e.g., tungsten carbide or VK10 hard alloy).[28] The outer octahedral cavity is pressed by 8 steel outer anvils. After mounting, the whole assembly is locked in a disc-type barrel with a diameter about 1 meter. The barrel is filled with oil, which pressurizes upon heating, and the oil pressure is transferred to the central cell. The synthesis capsule is heated up by a coaxial graphite heater. Temperature is measured with a thermocouple.[29]

[edit] Chemical vapor deposition

See also: Chemical vapor deposition of diamond

Chemical vapor deposition of diamond is a method of growing diamond from a hydrocarbon gas mixture. Since the early 1980s, this method has been the subject of intensive world-wide research. Whereas the mass-production of high-quality diamond crystals make the HPHT process the more suitable choice for industrial applications, the flexibility and simplicity of CVD setups explain the popularity of CVD growth in laboratory research. The advantages of CVD diamond growth include the ability to grow diamond over large areas and on various substrates, and the fine control over the chemical impurities and thus properties of the diamond produced. Unlike HPHT, CVD process does not require high pressures, as the growth typically occurs at pressures under 27 kPa.

The CVD growth involves substrate preparation, feeding varying amounts of gases into a chamber and energizing them. The substrate preparation includes choosing an appropriate material and its crystallographic orientation; cleaning it, often with a diamond powder to abrade a non-diamond substrate; and optimizing the substrate temperature (about 800 °C) during the growth through a series of test runs. The gases always include a carbon source, typically methane, and hydrogen with a typical ratio of 1:99. Hydrogen is essential because it selectively etches off non-diamond carbon. The gases are ionized into chemically active radicals in the growth chamber using microwave power, a hot filament, an arc discharge, a welding torch, a laser, an electron beam, or other means. One of the important factors in chamber design is that during the growth, the chamber materials are etched off by the plasma and can incorporate into the growing diamond. In particular, CVD diamond is often contaminated by silicon originating from the silica windows of the growth chamber or from the silicon substrate. Therefore, silica windows are either avoided or moved away from the substrate. Also, once boron-containing species are introduced into the chamber, it becomes unsuitable for growth of pure diamond.[22]

[edit] Detonation of explosives

Electron micrograph (TEM) of detonation nanodiamond
Main article: Detonation nanodiamond

Diamond nanocrystals (5 nm in diameter) can be formed by detonating certain carbon-containing explosives in a metal chamber. These nanocrystals are called "detonation nanodiamond". During the explosion, the pressure and temperature in the chamber become high enough to convert the carbon of the explosives into diamond. Detonation nanodiamond, used primarily in polishing applications, is only now beginning to reach the market in bulk quantities. It is produced primarily in China, Russia and Ukraine.[23]

[edit] Ultrasound cavitation

Micron-sized diamond crystals can be synthesized from a suspension of graphite in organic liquid at atmospheric pressure and room temperature using ultrasonic cavitation. The diamond yield is about 10% of the initial graphite weight. The estimated cost of diamond produced by this method is comparable to that of the HPHT method.[24][30] This technique requires relatively simple equipment and procedures, but it has only been reported by two research groups, and has no industrial use as of 2009.

[edit] Properties

Traditionally, the absence of crystal flaws is considered to be the most important quality of a diamond. Purity and high crystalline perfection make diamonds transparent and clear, whereas its hardness, optical dispersion (luster) and chemical stability (combined with marketing), make it a popular gemstone. High thermal conductivity is also important for technical applications. Whereas high optical dispersion is an intrinsic property of all diamonds, their other properties vary depending on how the diamond was created.

[edit] Crystallinity

Diamond can be one single, continuous crystal or it can be made up of many smaller crystals (polycrystal). Large single-crystal diamond is typically used in gemstones, whereas polycrystalline diamond is used for industrial applications such as mining and cutting tools. Within polycrystalline diamond, the diamond is often described by the average size (or grain size) of the crystals that make it up. Grain sizes range from nanometers to hundreds of micrometers, usually referred to as "nanocrystalline" and "microcrystalline" diamond, respectively.[9]

[edit] Hardness

A diamond's hardness varies depending primarily on its impurities and crystallinity. Nanocrystalline diamond produced through CVD diamond growth, for instance, can have a hardness ranging from 30% to 75% to that of single crystal diamond, and the hardness can be controlled for specific applications. Some synthetic single-crystal diamonds and HPHT nanocrystalline diamonds (see hyperdiamond) are harder than any known natural diamond.[31][32][33]

[edit] Impurities and inclusions

Main article: Crystallographic defects in diamond

Every diamond contain atoms other than carbon in concentrations detectable by analytical techniques. Those atoms can aggregate into macroscopic phases called inclusions. While impurities are generally avoided, they can be introduced intentionally as a way to control certain properties of the diamond. For instance, pure diamond is an electrical insulator, but diamond with boron added is an electrical conductor (and, in some cases, a superconductor),[34] allowing it to be used in electronic applications. Nitrogen impurities hinder movement of lattice dislocations (defects within the crystal structure) and put the lattice under compressive stress, thereby increasing hardness and toughness.[35]

[edit] Thermal conductivity

Unlike most electrical insulators, pure diamond is a good conductor of heat because of the strong covalent bonding within the crystal. The thermal conductivity of pure diamond is the highest among any known solid. However, it is reduced by the small amount (1.1 at. %) of 13C isotope naturally present; 13C acts as an inhomogeneity in the 12C diamond lattice, thereby reducing its thermal conduction. Therefore, single crystals of synthetic diamond enriched in 12C isotope (99.9%) have the highest thermal conductivity of any material, 30 W/cm·K at room temperature, five times higher than copper.[36]

[edit] Applications

[edit] Machining and cutting tools

Diamonds in an angle grinder blade

Diamond has long been used in machine tools, especially when processing non-ferrous alloys, as carbon dissolves in iron at the high temperatures created by high-speed machining. While natural diamond is still applied for this, synthetic diamond is much more popular, mostly because of better reproducibility of its mechanical properties. The usual form of diamond in cutting tools is micrometer-sized grains dispersed in a metal matrix (usually cobalt) sintered onto the tool. This is typically referred to in industry as polycrystalline diamond (PCD). PCD-tipped tools can be found in mining and cutting applications.[37] For the past fifteen years, work has been done to coat metallic tools with CVD diamond, and though the work still shows promise it has not significantly replaced traditional PCD tools.[38]

[edit] Thermal conductor

Because of excellent thermal conductivity and dielectric properties of diamond, it is commercially sold for heat sink applications.[39] Heat sinks are used in high-power semiconductor lasers;[40] in semiconductor technology, they prevent silicon and other semiconducting materials from overheating.[41]

Diamond's thermal conductivity is made use of by jewelers and gemologists who may employ an electronic thermal probe to separate diamonds from their imitations. These probes consist of a pair of battery-powered thermistors mounted in a fine copper tip. One thermistor functions as a heating device while the other measures the temperature of the copper tip: if the stone being tested is a diamond, it will conduct the tip's thermal energy rapidly enough to produce a measurable temperature drop. This test takes about 2–3 seconds.[8]

[edit] Windows

Diamond is hard, chemically inert, it has a high thermal conductivity and low thermal expansion, in contrast to many window materials used for the infrared and microwave parts of the spectrum. Therefore, diamond is starting to replace zinc selenide and other materials as the output window of high-power CO2 lasers[42] and gyrotrons. Those windows should have shapes of disks having large diameter (about 10 cm for gyrotrons) and small thickness (to reduce absorption). In these shape requirements, CVD diamond outperforms any other diamond varieties.[43][44]

[edit] Electronics

Diamond has potential uses as a semiconductor,[45] because it can be doped with impurities like boron and phosphorus. Since these elements contain one more or one less valence electron than carbon, they turn diamond into p-type or n-type semiconductor. Making a p-n junction by sequential doping of diamond with boron and phosphorus produces UV light emitting diodes (LEDs, at 235 nm).[46] Another useful property of diamond for electronics is high carrier mobility, which reaches 4500 cm2/(V·s) in single-crystal CVD diamond.[47] High mobility is favorable for high-frequency field-effect transitors. The wide band gap of diamond (5.5 eV) leads to the excellent dielectric properties. Combined with high mechnical stability of diamond, those properties are being used in prototype high-power switches for power stations.[48]

Conductive CVD diamond is a useful electrode under many circumstances.[49] Photochemical methods have been developed for covalently linking DNA to the surface of polycrystalline diamond films produced through CVD.[50] In addition, diamonds can detect redox reactions that cannot ordinarily be studied and in some cases degrade redox-reactive organic contaminants in water supplies. Because diamond is mechanically and chemically stable, it can be used as an electrode under conditions that would destroy traditional materials. For such reasons, waste water treatment of organic effluents using diamond,[51] as well as production of strong oxidants, have been reported.[52]

Diamond transistors are functional to much higher temperatures than silicon devices and are resistant to chemical and radiation damage. While no diamond transistors have yet been successfully integrated into commercial electronics, they show promise for use in exceptionally high power situations and hostile environments.[53]

Diamond shows great promise as a potential radiation detection device. It is radiation hard and has a wide bandgap of 5.5 eV (at room temperature). Therefore, it is employed in applications such as the BaBar detector at the Stanford Linear Accelerator[54] or BOLD (Blind to the Optical Light Detectors for VUV solar observations).[55][56] Pure single-crystal synthetic diamonds are approaching the very high purity and crystallographic structure perfection required to replace silicon in devices such as synchrotrons used in CT scanning;[47][57] they will be able to sustain the increased intensities of next generation light sources.[58]

CVD diamond growth has been used in conjunction with lithographic techniques to encase microcircuits inside diamond. The CVD process is also used to create designer diamond anvils as a novel probe for measuring electric and magnetic properties of materials at ultra high pressures using a diamond anvil cell.[59]

[edit] Gemstones

Colorless gem cut from diamond grown by chemical vapor deposition

Diamonds for use as gemstones are grown by HPHT[18] or CVD[60] methods. They are available in yellow or blue colors, and to a lesser extent colorless (or white). The yellow color comes from nitrogen impurities in the manufacturing process while the blue color comes from boron.[17] Other colors such as pink or green are achievable after synthesis using irradiation.[61] Several companies also offer memorial diamonds grown using cremated remains. Gem-quality diamond is currently produced by the following producers listed in the table below.

Company Method Color
Apollo Diamond CVD colorless
Chatham HPHT yellow, blue
D.NEA yellow, blue, white
Gemesis yellow
New Age Diamonds yellow, green, red

Gem-quality diamonds grown in a lab can be chemically, physically and optically identical to naturally occurring ones, although they can be distinguished by spectroscopy in infrared, ultraviolet, or X-ray wavelengths. The DiamondView tester from De Beers uses UV fluorescence to detect trace impurities of nitrogen, nickel or other metals in HPHT or CVD diamonds.[9]

The mined diamond industry is evaluating marketing and distribution countermeasures to these less expensive alternatives. The three largest distributors of natural diamonds have made public statements about selling their diamonds with full disclosure and have implemented measures to laser-inscribe serial numbers on their gemstones.[60]

[edit] See also

Search Wikimedia Commons Wikimedia Commons has media related to: Synthetic diamond

[edit] References

  1. ^ J. B. Hannay (1879). "On the Artificial Formation of the Diamond". Proc. R. Soc. Lond. 30: 450–461. doi:10.1098/rspl.1879.0144. 
  2. ^ C. Royère (1999). "The electric furnace of Henri Moissan at one hundred years: connection with the electric furnace, the solar furnace, the plasma furnace?". Annales pharmaceutiques françaises 57: 116. PMID 10365467. 
  3. ^ H. Moissan (1894). "Nouvelles expériences sur la reproduction du diamant". Comptes Rendus 118: 320. 
  4. ^ 0. Ruff. "Über die Bildung von Diamanten". Zeitschrift für anorganische und allgemeine Chemie 99 (1): 73–104. doi:10.1002/zaac.19170990109. 
  5. ^ K. Nassau (1980). Gems made by Man. Chilton Book Co.. pp. 12–25. ISBN 0801967732. 
  6. ^ J. Willard Hershey Ph.D. (1940). Book of Diamonds. Heathside Press, New York. p. 123. ISBN 0486418162. http://www.farlang.com/diamonds/hershey-diamond-chapters/page_131. 
  7. ^ a b K. Lonsdale (1962). "Further Comments on Attempts by H. Moissan, J. B. Hannay and Sir Charles Parsons to Make Diamonds in the Laboratory". Nature 196: 104. doi:10.1038/196104a0. http://67.50.46.175/paperspdf/lons-k1962.pdf. 
  8. ^ a b M. O'Donoghue (2006). Gems. Elsevier. p. 473. ISBN 0-75-065856-8. 
  9. ^ a b c d e f g h i A. S. Barnard (2000). The diamond formula: diamond synthesis-a gemological perspective. Butterworth-Heinemann. pp. 3–9; 31–50. ISBN 0750642440, 9780750642446. 
  10. ^ C. A. Parson (1907). "Some notes on carbon at high temperatures and pressures". Proceedings of the Royal Society of London 79a: 532. doi:10.1098/rspa.1907.0062. http://67.50.46.175/paperspdf/pars-ca1907.pdf. 
  11. ^ C.H. Desch (1928). "The Problem of Artificial Production of Diamonds". Nature 121: 799. doi:10.1038/121799a0. 
  12. ^ a b c d R. M. Hazen (1999). The diamond makers. Cambridge University Press. pp. 100–113. ISBN 0521654742. 
  13. ^ H. T. Hall (1960). "Ultra-high pressure apparatus". Rev. Sci. Instr. 31: 125. doi:10.1063/1.1716907. http://67.50.46.175/pdf/19600162.pdf. 
  14. ^ "Tracy Hall, Leading Figure in Diamond Synthesis, Dies Aged 88". element six. http://www.e6.com/en/newscentre/pressreleases/name,901,en.html. Retrieved on 2009-05-05. 
  15. ^ H. Liander and E. Lundblad (1955). "Artificial diamonds". ASEA Journal 28: 97. 
  16. ^ General Electric v. Sung, 843 F. Supp. 776 (D. Mass. 1994): "granting production injunction against Iljin Diamond"
  17. ^ a b R. C. Burns, V. Cvetkovic and C. N. Dodge (1990). "Growth-sector dependence of optical features in large synthetic diamonds". Journal of Crystal Growth 104: 257. doi:10.1016/0022-0248(90)90126-6. 
  18. ^ a b R. Abbaschian et al. (2005). "High pressure-high temperature growth of diamond crystals using split sphere apparatus". Diam. Rel. Mater. 14: 1916. doi:10.1016/j.diamond.2005.09.007. 
  19. ^ W. G. Eversole Synthesis of diamond, US patent 3030187 and 3030188 (1962)
  20. ^ J. C. Angus et al. (1968). "Growth of Diamond Seed Crystals by Vapor Deposition". J. Appl. Phys. 39: 2915. doi:10.1063/1.1656693. 
  21. ^ B.V. Deryagin and D. V. Fedoseev (1970). "Epitaxial Synthesis of Diamond in the Metastable Region". Rus. Chem. Rev. 39: 783. 
  22. ^ a b M Werner et al. (1998). "Growth and application of undoped and doped diamond films". Rep. Prog. Phys. 61: 1665. doi:10.1088/0034-4885/61/12/002. 
  23. ^ a b V. Yu. Dolmatov (2006). "Development of a rational technology for synthesis of high-quality detonation nanodiamonds". Russian Journal of Applied Chemistry 79: 1913. doi:10.1134/S1070427206120019. 
  24. ^ a b E. M. Galimov et al. (2004). "Experimental Corroboration of the Synthesis of Diamond in the Cavitation Process". Doklady Physics 49: 150. doi:10.1134/1.1710678. 
  25. ^ "HPHT synthesis". International Diamond Laboratories. http://www.diamondlab.org/80-hpht_synthesis.htm. Retrieved on 2009-05-05. 
  26. ^ H. T. Hall (1958). "Ultrahigh-Pressure Research: At ultrahigh pressures new and sometimes unexpected chemical and physical events occur". Science 128: 445. doi:10.1126/science.128.3322.445. http://67.50.46.175/pdf/19580097.pdf. 
  27. ^ E. Ito (2007). G. Schubert. ed. Multianvil cells and high-pressure experimental methods, in Treatise of Geophysics. Elsevier, Amsterdam. p. 197–230. ISBN 0812922751. 
  28. ^ M. G. Loshak and L. I. Alexandrova (2001). "Rise in the efficiency of the use of cemented carbides as a matrix of diamond-containing studs of rock destruction tool". Int. J. Refractory Metals and Hard Materials 19: 5. doi:10.1016/S0263-4368(00)00039-1. 
  29. ^ N. Pal'yanov et al. (2002). "Fluid-bearing alkaline carbonate melts as the medium for the formation of diamonds in the Earth's mantle: an experimental study". Lithos 60: 145. doi:10.1016/S0024-4937(01)00079-2. 
  30. ^ A. Kh. Khachatryan et al. (2008). "Graphite-to-diamond transformation induced by ultrasonic cavitation". Diam. Relat. Mater. 17: 931. doi:10.1016/j.diamond.2008.01.112. 
  31. ^ H. Sumiya (2005). "Super-hard diamond indenter prepared from high-purity synthetic diamond crystal". Rev. Sci. Instrum. 76: 026112. doi:10.1063/1.1850654. 
  32. ^ C-S Yan et al. (2005). "Ultrahard diamond single crystals from chemical vapor deposition". Phys. Stat. Solidi (a) 201: R25. doi:10.1002/pssa.200409033. 
  33. ^ V. Blank et al. (1998). "Ultrahard and superhard phases of fullerite C60: comparison with diamond on hardness and wear". Diamond and Related Materials 7: 427. doi:10.1016/S0925-9635(97)00232-X. http://www.nanoscan.info/files/article_03.pdf. 
  34. ^ E. Ekimov et al. (2004). "Superconductivity in diamond". Nature 428: 542. doi:10.1038/nature02449. http://www.nims.go.jp/NFM/paper1/SuperconductingDiamond/01nature02449.pdf. 
  35. ^ S. A. Catledge (1999). "Effect of nitrogen addition on the microstructure and mechanical properties of diamond films grown using high-methane concentrations". Journal of Applied Physics 86: 698. doi:10.1063/1.370787. 
  36. ^ L. Wei et al. (1993). "Thermal conductivity of isotopically modified single crystal diamond". Phys. Rev. Lett. 70: 3764. doi:10.1103/PhysRevLett.70.3764. 
  37. ^ R. T. Coelho et al. (1995). "The application of polycrystalline diamond (PCD) tool materials when drilling and reaming aluminum-based alloys including MMC". International journal of machine tools & manufacture 35: 761. doi:10.1016/0890-6955(95)93044-7. 
  38. ^ W. Ahmed et al. (2003). "Diamond films grown on cemented WC-Co dental burs using an improved CVD method". Diamond and Related Materials 12: 1300. doi:10.1016/S0925-9635(03)00074-8. 
  39. ^ "CVD Thick-Film Diamond Heat Spreaders". sp3 diamond technologies. http://www.sp3inc.com/spreader.htm. Retrieved on 2009-05-05. 
  40. ^ M. Sakamoto, J. G. Endriz, D. R. Scifres (1992). "120 W CW output power from monolithic AlGaAs (800 nm) laser diode array mounted on diamond heatsink". Electronics Letters 28 (2): 197–199. doi:10.1049/el:19920123. 
  41. ^ US Patent 6924170 - Diamond-silicon hybrid integrated heat spreader
  42. ^ D. C. Harris (1999). Materials for infrared windows and domes: properties and performance. SPIE Press. pp. 303–334. ISBN 0819434825. 
  43. ^ T. Inai et al. (1999). "The diamond window for a milli-wave zone high power electromagnetic wave output". New Diamond 15: 27. 
  44. ^ G. S. Nusinovich (2004). Introduction to the physics of gyrotrons. JHU Press. p. 229. ISBN 0801879213. 
  45. ^ A. Denisenko and E. Kohn (2005). "Diamond power devices. Concepts and limits". Diamond and Related Materials 14: 491. doi:10.1016/j.diamond.2004.12.043. 
  46. ^ S. Koizumi et al. (2001). "Ultraviolet Emission from a Diamond pn Junction". Science 292: 1899. doi:10.1126/science.1060258. 
  47. ^ a b J. Isberg et al. (2002). "High Carrier Mobility in Single-Crystal Plasma-Deposited Diamond". Science 297: 5587. doi:10.1126/science.1074374. 
  48. ^ J. Isberg, M. Gabrysch, A. Tajani, and D.J. Twitchen (2006). "High-field Electrical Transport in Single Crystal CVD Diamond Diodes". Advances in Science and Technology 48: 73. doi:10.4028/www.scientific.net/AST.48.73. 
  49. ^ M. Panizza and G. Cerisola (2005). "Application of diamond electrodes to electrochemical processes". Electrochimica Acta 51: 191. doi:10.1016/j.electacta.2005.04.023. 
  50. ^ C. E. Nebel et al. (2007). Inhomogeneous DNA bonding to polycrystalline CVD diamond. 16. p. 1648. doi:10.1016/j.diamond.2007.02.015 Diamond and Related Materials. 
  51. ^ D. Gandini, E. Mahé, P.A. Michaud, W. Haenni, A. Perret, Ch. Comninellis (2000). "Oxidation of carbonylic acids at boron-doped diamond electrodes for wastewater treatment". Journal of Applied Electrochemistry 20: 1345. doi:10.1023/A:1026526729357. 
  52. ^ P.A. Michaud, E. Mahé, W. Haenni, A. Perret, Ch. Comninellis (2000). "Preparation of peroxodisulfuric acid using Boron-Doped Diamond thin film electrodes". Electrochemical and Solid-State Letters 3: 77. doi:10.1149/1.1390963. 
  53. ^ T. A. Railkar et al. (2000). "A critical review of chemical vapor-deposited (CVD) diamond for electronic applications". Critical Reviews in Solid State and Materials Sciences 25: 163. doi:10.1080/10408430008951119. 
  54. ^ M. Bucciolini (2005). "Diamond dosimetry: Outcomes of the CANDIDO and CONRADINFN projects". Nuclear Instruments and Methods in Physics Research A 552: 189. doi:10.1016/j.nima.2005.06.030. 
  55. ^ "Blind to the Optical Light Detectors". Royal Observatory of Belgium. http://bold.oma.be/. Retrieved on 2009-05-05. 
  56. ^ A. BenMoussa et al. (2008). "New developments on diamond photodetector for VUV Solar Observations". Semiconductor Science and Technology 23: 035026. doi:10.1088/0268-1242/23/3/035026. 
  57. ^ J. Heartwig et al.. "Diamonds for Modern Synchrotron Radiation Sources". European Synchrotron Radiation Facility. http://www.esrf.eu/UsersAndScience/Publications/Highlights/2005/Imaging/XIO5. Retrieved on 2009-05-05. 
  58. ^ A. M. Khounsary et al.. "Diamond Monochromator for High Heat Flux Synchrotron X-ray Beams". Argonne National Laboratory. http://www.aps.anl.gov/Facility/Technical_Publications/lsnotes/ls215/ls215.html. Retrieved on 2009-05-05. 
  59. ^ "Magnetic susceptibility measurements at high pressure using designer diamond anvils". Rev. Sci. Instrum. 74: 2467. 2003. doi:10.1063/1.1544084. 
  60. ^ a b A. Yarnell (February 2, 2004). "The many facets of man-made diamonds". Chemical and Engineering News (American Chemical Society): pp. 26–31. http://pubs.acs.org/cen/coverstory/8205/8205diamonds.html. Retrieved on 2009-05-04. 
  61. ^ J. Walker (1979). "Optical absorption and luminescence in diamond". Rep. Prog. Phys. 42: 1605. doi:10.1088/0034-4885/42/10/001. 

[edit] Further reading

[edit] External links

Wikisource
Retrieved from "http://en.wikipedia.org/wiki/Synthetic_diamond"
Personal tools