The Ultimate Semiconductor

Among many of diamond's beneficial properties are its semiconductor capabilities. The structure of diamond forms the basis of almost all semiconductors including the most prevailing material today silicon. However, with its high hole mobility and high temperature stability of all possible semiconductor materials, diamond can be the dream CPU chip for future supercomputers (Fig. 3.7). Moreover, by possessing unmatched thermal conductivity, diamond will be the only semiconductor that can...

Diamond Stars

Jane Taylor composed the famous lyric diamond in the sky about 200 years ago, she could not have imagined that her figurative poetry would foretell the monumentous scientific discovery made in the 20th century. As it turns out, real diamonds are not only in the sky, but it may even be the most common solid in the universe. In addition, as will be introduced in Chapters 2 and 3, diamond is also a very unique and an essential material for a myriad of different applications. Thus, the...

Dynamite Diamond

Size Distribution Nanodiamonds

Diamond may be formed by direct conversion of graphite with explosion-produced shock waves. Alternatively, the explosive can itself provide the carbon source (e.g. by dynamite detonation) to form diamond. In this case, the dynamite may decompose to form carbon and compressed gas. Due to the presence of instantaneous pressure and temperature, the carbon network in dynamite may rearrange to form diamond. However, such diamond particles, being extremely small, are immediately liquefied by the high...

Micron Diamond Applications

Because of the poor diamond yield and the excessive steps required to recover and purify diamond, shock wave compressed micron diamonds are intrinsically expensive (e.g. four times more than pulverized micron diamond of the same size), hence, their market size is limited. The annual production of shock wave compressed micron diamonds is less than 1 ton with the sales value of about 10 million that is less than 1 10 of conventional micron diamond. Hence, they are mainly used in premium...

Nanodiamond Applications

Nanodiamond Structure

Being extremely small and with high amount of surface atoms, nanodiamond has diversified applications. Some applications involve using the superhard properties of diamond. The others may adapt low frictional coefficient of diamond (Table 7.1). 7.1 LUBRICATION OF ENGINE OIL AND MACHINE GREASE Nanodiamond can reduce significantly the frictional coefficient by coating on the sliding surface. The nanodiamond coating reduces the contact area. Moreover, the inertness of the diamond surface reduces...

Shock Wave Compressed Diamond

Hexagonal Cubic Diamond

Instead of breaking large diamond grains to form micron-sized particles, shock wave may be applied to collapse graphite. Due to the instantaneous rises of pressure and temperature diamond crystallites are formed. However, as the high pressure is maintained for only a few microseconds, such crystallites are virus sized (e.g. 50 nm). But due to the slow cooling of the charge nano particles are sticking together to form sintered polygrits up to 50 microns (Fig. 5.19). The direct transformation of...

Cvd Diamond Formation

Although graphite is stable at low pressures but this refers to large structures of more than hundreds atoms. If the clusters of atoms are less than several hundreds, diamond, bucky balls, or carbon nano tubes may still be more stable. This is because the edges of two-dimensional graphene planes are more energetic than three-dimensional diamond surfaces, bucky balls with no ends, and rolled graphene planes with less ends. Hence, diamond, bucky balls and carbon nanotubes may form in smaller...

Diamond Synthesis Routes

Diamond is everywhere inside supernovae, with star dusts, in meteorites, around impact craters, and under ground, consequently, there are numerous ways that can form diamond. However, all these synthesis routes employ a common strategy, namely, by squeezing loosely held carbon atoms surrounded by contact neighbors of 0 (sp0, e.g. C), 1 (spa5, e.g. C2), 2 (sp1, e.g. car-byne, C C ), 3 (sp2, e.g. graphite), and 4 (sp3, e.g. methane) to make them more compact by forming a continuous network of...

Historical Milestones Of Diamond Synthesis

Previously it was believed that diamond was never synthesized before the 20th century. However, in the light of the discovery of CVD methods for depositing diamond, it is possible that diamond could be formed in regions where the burning of hydrocarbon gas is incomplete. Minute diamond-like particles could have been made inadvertently when Cro-Magnon made wall paintings by brushing torches against a cave wall some 35 thousand years ago (DeVries, 1995). If this was the case, then diamond...

Diamondlike Carbon

Diamond-like carbon can be coated on a variety of substrates including metals e.g. steel , polymers e.g. teflon , and ceramics e.g. glass . The coating provides certain diamond attributes, such as high wear resistance, low frictional coefficient, and extreme chemical inertness. There are different methods that may produce DLC, each with specific characteristics. Figure 10.1 shows the classification of DLC types based on the diamond-like bonding sp3 and graphitic bonding sp2 for carbon atoms,...

Fluorinated DLC for Tribological Applications

Diamond-like carbon DLC can be slippery with a frictional coefficient on par with Teflon e.g. 0.1 . Hydrogen terminated DLC may be more slippery than pure carbon DLC, but fluorinated DLC can be super slippery with frictional coefficient less than engine oil 0.01 . The fluorinated diamond is actually superhard Teflon that may be named dialon. Dialon is not only virtually frictionless, it is also super hydrophobic, more so than even lotus leaves. In fact, if dialon is coated onto heart valves, it...

References

Gerberich, L. Kruckeberg, and D. R. Kania, Biocompatibility of chemical-vapour-deposited diamond, Biomater, 16, 483-488 1995 . 2. A. F. Azevedo, E. J. Corat, N. G. Ferreira, and V. J. Trava-Airoldi, Wettability and corrosion tests of diamond films grown on Ti6Al4V alloy, Surf. Coatings Tech, 194, 271-275 2005 . 3. S.-J. Yu, M.-W. Kang, H.-C. Chang, K.-M. Chen, and Y.-C. Yu, Bright fluorescent nanodiamonds No photobleaching and low cytotoxic-ity, J. Am. Chem. Soc,...

Cvd Diamond Film And Pvd Diamondlike Carbon Dlc Coating

Hot Filament Diamond China

Diamond is also grown metastably in partial vacuum to form either freestanding films or adhered coatings. Diamond films of up to 1 mm in thickness, and up to 30 cm wide, can be precipitated by a variety of CVD methods e.g. hot filament, microwave plasma, Figure 4.17. The production cubic presses in Huanghe the largest diamond plant in the world , China that can manufacture over 3 million carats a day. Figure 4.17. The production cubic presses in Huanghe the largest diamond plant in the world ,...

Dialon Applications

Dialon may have numerous applications. For example, it can be coated on plastic material to improve the air tightness. For example, Figure 10.11. Frictional coefficient between steel ball and DLC coated high speed steel plate. Figure 10.11. Frictional coefficient between steel ball and DLC coated high speed steel plate. the interior of PET bottles can be coated with dialon by inserting the container with an electrode that echoes with the exterior electrode in radio frequency e.g. 15.6 MHz . The...

Htermi nation Otermi nation Hl0

Conductive layer thickness lt 10 nm Surface hole concentration -1013 cm 2 Hydrophobic Negative electron affinity Conductive layer thickness lt 10 nm Surface hole concentration -1013 cm 2 Hydrophobic Negative electron affinity Hydrophilic Positive electron affinity Figure 8.6. Schematic diagram of the H- and O-terminated 00 1 diamond surfaces and their physical properties. Source From Ref. 26. Diamond in Biomedical Applications 169 11 Figure 8.7. An X-ray radiogram taken after an implantation...

Liquid Phase Growth Of Diamond At Low Pressure

Phast Diagram Calcium Titanate

Gem diamond crystals have been grown by CVD methods at partial vacuum, but as graphite is the stable phase, the growth rate of diamond must be kept low lest graphitic carbons are formed. On the other hand, the growth of gem diamonds in molten alloy e.g. invar composition under ultrahigh pressure can be increased, but the volume of the apparatus is severely limited. It would be ideal if diamond can grow in liquid phase at atmospheric pressure. In this case, not only the growth rate can be high,...

Dialon Coating

The fluorinated DLC is akin to teflon that is essentially fluorine coated diamond atoms that form a single file. In fact, this structure maybe named dialon for diamond-teflon for future reference. Figure 10.9 is a schematic diagram of teflon compound. The fluorination cannot only lubricate the DLC, but also enhance its adherence to the substrate, particularly on the surface of polymers. Moreover, the fluorine atoms attached to DLC can repel water or other polarized molecules so the surface is...

The Role Of Hydrogen Atoms

In 1968, Henry Hibshman suggested that hydrogen may be used to stabilize diamond growth during the pyrolysis of carbonaceous gases. In 1971, John Angus began to duplicate Eversole's process using a hot filament process. This time he tried adding hydrogen gas to speed up the diamond growth. In 1976, Derjaquin starting experimenting the CVD growth of diamond by glow discharge. Again, he found that hydrogen addition was beneficial to his process. 1n 1981, Setaka first introduced microwave plasma...

The Split Die Technology

The belt apparatus is too bulky for making gem diamonds on one hand, and the split sphere is too complicated for making one crystal at a time. The solution is to extend the split chamber to form a longitudinal chamber that allow multiple crystal to grow simultaneously Sung, Chien-Min, US Patent No. 7,128,547 . The growth conditions of each diamond crystal can be precisely controlled by Figure 11.8. Polished artificial diamond gems with different colors. its own temperature monitor with real...

Amorphous Diamond Solar Cell

The merit of amorphous diamond to convert either light or heat to electricity can be applied to solar cell panels or thermal electrical generators. For example, amorphous diamond was over covered coated on indium tin oxide ITO , the transparent electrical conductor that was coated on a glass substrate. This panel was separated from another ITO coated glass by glass bead spacer. The gap was sealed around and the space was pumped down to high vacuum 10-6 torr . This panel was exposed to a xenon...