Material diamond-like carbon

During carbonization of PAN, an extensive-random network of graphitic ribbons is formed which heis a stable configuration. I n addition, it is speculated that some tetrahedral (sp (diamond) bonds are formed (which would account for the hardness of these materials). 1 1 The presence of diamond structure in a similar material, diamond-like carbon, is well established (see Ch. 14). The diamond structure is reviewed in Ch. 2, Sec. 3.0. These two factors, ribbon network and tetrahedral bonds, would preventfurther ordering ofthe staicture, regardless of the graphitization temperature. 

Deposition of Diamond-Like Carbon Materials Science... 

Grill, A., Patel, V., and Meyerson, B. S., Applications of Diamond-Like Carbon in Computer Technology, in Applications of Diamond Films and Related Materials (Y. Tzeng, et al., eds.), Elsevier Science Publishers, pp. 683-689 (1991)... 

Grill, A., Tribology of Diamond-like Carbon and Related Materials An Updated Review, Surf. Coat. Technol., Vol. 94/ 95,1997, pp. 507-513. 

Raman spectroscopy A nondestructive method for the study of the vibrational band structure of materials, which has been extensively used for the characterization of diamond, graphite, and diamond-like carbon. Raman spectroscopy is so far the most popular technique for identifying sp bonding in diamond and sp bonding in graphite and diamond-like carbon. 

Plasma Synthesis The use of plasma methods has lead to a new range of materials having unique properties. An example is the family of amorphous elemental hydrides (eg cr-C H Of -Si H or-P H) which contain a variable proportion of H from almost zero to 50 atomic %. The carbon films, known variously as "hard carbon", "diamond-like carbon", " a-carbon" etc (9 ) - These layers are of considerable interest because of their optical and abrasion-resistant properties etc (Table I). The properties of these Gr-carbon films, can be tailored by modifying the plasma parameters. 

Various forms of carbon material such as graphite, diamond, carbon nanotubes (fibers), and amorphous carbon-containing, diamond-like carbon have been compared and analyzed for their potential application in the fields of flat panel displays and lighting elements.48... 

V. Anita, T. Butuda, T. Maeda, K. Takizawa, N.Saito, 0. Takai, Effect of N doping on properties of diamond-like carbon thin films produced by RF capacitively coupled chemical vapor deposition from different precursors., Diamond and Related Materials, vol. 13, pp. 1993-1996, 2004. 

H. Nakazawa, A. Sudoh, M. Suemitsu, K. Yasui, T. ltoh,T. Endoh, Y. Narita, M. Mashita, Mechanical and tribological properties of boron, nitrogen-coincorporated diamond-like carbon films prepared by reactive radio-frequency magnetron sputtering., Diamond and Related Materials, vol. 19, pp. 503-506, 2010. 

GEMSTONES-GEMSTONE MATERIALS] (Vol 12) Diamond-like carbon (DLC)... 

Carbon materials liave particular characteristics due to differences in chemical bond formation. Allotropic forms of carbon drat luive been discovered can be categorized into five types from file standpoint of the type of hybridization of the valence orbitals (1) sp -hybridization (2) sp -hybridization (3) sp-hybrid-ization (4) mixed hybridization (sp + sp ) and (5) a valance state characterized by a fractional degree of hybridization (sp , where 1 diamond-like carbon, and fullcrcnes correspond to groups (1), (3), (4), and (5), respectively. 

Diamond-like carbon material should still perform well even if it is delaminated. It has been observed that bone marrow cells do not react to the presence of DLC particulates, and hence, neither inflammatory nor toxic reaction is expected in the body from the use of DLC. The absence of a toxic response, besides the wear and tribological properties, makes DLC coatings attractive for long-term use where biocompatibility is necessary because of the biological system s natural response. 

Diamond-like carbon can be alloyed with toxic materials. This is necessary when no cell adhesion should be allowed specifically when equipments or implants are of temporary use. When this alloy makes contact with the biological environment, the cytotoxic materials, like copper, vanadium, and silver, inhibit cell growth on the material surface because of the toxic action of the alloy. Changing alloy components can control the bioreactions. When DLC is mixed with silicon oxide a reduction of the inflammatory reactions is observed. 

Diamond-like carbon since its inception in 1962 has found applications in some very important areas. These applications include coatings used in scratch-resistant optics, razor blades, prosthesis in medical applications electron emission surfaces in electronics as an insulator material for copper heat sinks in semiconductors such as solar cells and sensors for visible to infrared radiations and as structural materials such as deuterated DLC film used for neutron storage in advanced research instrumentation. As technology matures the unique properties of DLC will find new and important applications. 

Grill, A. Diamond-like carbon coatings as biocompatible materials—an overview. Diamond Relat. Mater. 2003, 12, 166-170. 

Cataldo, F. Capitani, D. Preparation and characterization of carbonaceous matter rich in diamond-like carbon and carbyne. Materials Chem. Phys. 1999, 59, 225-231. 

Besides the proper diamond flhns obtained by vapor deposition, the same method also allows for the preparation of further, similar materials. These include the so-called a-C H- and a-C-phases that are alternatively termed diamond-like carbon (DLC) films. ... 

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