Diamond property

Dolmatov VY (2001) Detonation synthesis uitradispersed diamonds properties and applications. Uspekhi Khimii 70(7) 687-708, in Russian... 

The carbon isotopic composition of diamonds has been studied for many years (e.g., Galimov etal., 1978 Deines, 1980 Galimov, 1984). These early studies attempted to correlate diamond properties such as color and form with carbon isotopic composition in some form of classification... 

Komarov, W.F. Petrov, E.A. Sakovitch, G.V. Klimov, A.V. Ultra dispersed detonation diamond properties and applications. In Advances in New Diamond Science and Technology, Sato, K., Fujimori, N., Fukunaga, O., Kamo, M., Okushi, H., Yoshikawa, M., Eds. MYU Tokyo, 1994. 

Apart from those mentioned above, there are other contaminations known for diamond films, too. Oxygen and silicon are frequently observed with the latter being incorporated into the lattice in a substitutional way as well. Oxygen and further impurities like sulfur or metallic defects have not yet been studied in sufficient detail to give a final statement on their arrangement in the lattice and on their influence on the diamond properties. Calculations indicate that boron, nitrogen, phosphorous, and silicon are the only dopants suitable for a stable incorporation into the lattice. 

Dolmatov VY. Detonation synthesis ultradispersed diamonds properties and apphca-tions. Rnss Chem Rev 2001 70 607. 

Table 10.1 summarizes some of the sahent physical properties of diamond and graphite as they will be needed in the remainder of this chapter. We compare them with those of silicon as the closest Idn to diamond. Some of the outstanding properties of diamond such as its superior hardness, chemical inertness, and high thermal conductivity are generally known nevertheless, it is instructive to briefly review these and other diamond properties in context. 

A related advantage of studying crystalline matter is that one can have synnnetry-related operations that greatly expedite the discussion of a chemical bond. For example, in an elemental crystal of diamond, all the chemical bonds are equivalent. There are no tenninating bonds and the characterization of one bond is sufficient to understand die entire system. If one were to know the binding energy or polarizability associated with one bond, then properties of the diamond crystal associated with all the bonds could be extracted. In contrast, molecular systems often contain different bonds and always have atoms at the boundary between the molecule and the vacuum. 

Another example of epitaxy is tin growdi on the (100) surfaces of InSb or CdTe a = 6.49 A) [14]. At room temperature, elemental tin is metallic and adopts a bet crystal structure ( white tin ) with a lattice constant of 5.83 A. However, upon deposition on either of the two above-mentioned surfaces, tin is transfonned into the diamond structure ( grey tin ) with a = 6.49 A and essentially no misfit at the interface. Furtliennore, since grey tin is a semiconductor, then a novel heterojunction material can be fabricated. It is evident that epitaxial growth can be exploited to synthesize materials with novel physical and chemical properties. 

The isotope boron-10 is used as a control for nuclear reactors, as a shield for nuclear radiation, and in instruments used for detecting neutrons. Boron nitride has remarkable properties and can be used to make a material as hard as diamond. The nitride also behaves like an electrical insulator but conducts heat like a metal. 

Containers less than bulk must bear the red diamond-shaped "FLAMMABLE LIQUID" label. Bulk containers must display the red "FLAMMABLE" placard in association with the UN1090 identification. Fire is the main ha2ard in emergencies resulting from spills. Some manufacturers provide transportation emergency response information. A listing of properties and ha2ard response information for acetone is pubHshed by the U.S. 

Hardness. The hardness (qv), or related property abrasiveness, is an important filler property. Hardness is determined by comparison to materials of known hardness on the Mohs scale. On this nonlinear scale, diamond is rated 10, quartz 7, calcite 3, and talc 1. The abrasiveness of a filler is also dependent on psd and the presence of impurities, eg, ka olin clay (Mohs hardness of 3) can be quite abrasive because of the presence of quartz impurities. 

Diamond is supreme among natural gemstones ia H, RI, and DISP. Table 3 shows the steady improvement ia the sequence of diamond imitations, the aim being to produce a colorless, adequately hard material having closely matching optical properties. The iatroduction of synthetic cubic 2irconia ia 1976 brought about a sufficiently close match. 

Table 3. Properties of Diamond and Synthetic Gemstone Materials ...

Several gemstone species occur in various colors, depending on the presence of impurities or irradiation-induced color centers. Examples are the beryl, comndum, and quart2 families. Quart2 has poor optical properties (RI = 1.55, DISP = 0.013), but becomes of gemological interest when it exhibits attractive colors. Any material can have its color modified by the addition of various impurities synthetic mby, sapphires, and spinel are produced commercially in over 100 colors (2). Synthetic cubic 2irconia has been made in essentially all colors of the spectmm (11), but only the colorless diamond imitation is produced commercially in any quantity. 

Table 4. Properties of Nonmetallic (Diamond-Like) Nitrides...

A fully automated microscale indentor known as the Nano Indentor is available from Nano Instmments (257—259). Used with the Berkovich diamond indentor, this system has load and displacement resolutions of 0.3 N and 0.16 nm, respectively. Multiple indentations can be made on one specimen with spatial accuracy of better than 200 nm using a computer controlled sample manipulation table. This allows spatial mapping of mechanical properties. Hardness and elastic modulus are typically measured (259,260) but time-dependent phenomena such as creep and adhesive strength can also be monitored. 

A wide range of cutting-tool materials is available. Properties, performance capabilities, and cost vary widely (2,7). Various steels (see Steel) cast cobalt alloys (see Cobalt and cobalt alloys) cemented, cast, and coated carbides (qv) ceramics (qv), sintered polycrystalline cubic boron nitride (cBN) (see Boron compounds) and sintered polycrystalline diamond tbin diamond coatings on cemented carbides and ceramics and single-crystal natural diamond (see Carbon) are all used as tool materials. Most tool materials used in the 1990s were developed during the twentieth century. The tool materials of the 1990s... 

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