Carbon chemical vapor deposition

B) Yudasaka, M. Kikuchi. R. Ohki, Y. Yoshimura, S. Nitrogen-containing carbon nanotube growth from Ni-phthalocyanine by chemical vapor deposition Carbon 1997, 35, 195. 

Graphite shows very anisotropic thermal properties as a result of its crystal structure. This is because graphite possesses two-dimensional hexagonal network structures and the layers are held together very loosely by weak forces. For example, chemical vapor deposited carbon, which is manufactured with heat treatment at 3000°C after the deposition and possesses almost ideal graphite structures, has a thermal conductivity of 2,000 W/m-K (at room temperature) parallel to the layers and 10 W/m K in the perpendicular direction as shown in figure 1. This value in the parallel direction is approximately 4-5 times more than the value of silver or copper, which are typical high thermal conductivity metals. 

K. Kwok and W.S. Chiu, Growth of carbon nanotubes by open-air laser-induced chemical vapor deposition. Carbon, 43, 437 146 (2005). 

Lee LY, Lee SF. et ah. Effects of potassium hydroxide post-treatments on the field-emission properties of thermal chemical vapor deposited carbon nanotubes. Journal of Nanoscience and Nanotechnology, 2011. 11(12) 11185-11189. 

Wang, J.J. et al. Synthesis of carbon nanosheets by inductively coupled radio-frequency plasma enhanced chemical vapor deposition. Carbon 42, 2867-2872, 2004. 

Kinoshita, H., Kume, I., Sakai, H., Tagawa, M.and Ohmae, N., High growth rate of vertically aligned carbon nanotubes using a plasma shield in microwave plasma-enhanced chemical vapor deposition. Carbon, 42, 2004, XTii-llll. 

Kong, J., Cassell, A., Dai, H. - Chemical vapor deposition of methane for single walled carbon nanotuhes , Chem. Phys. Lett. 292 (1998) 567-574 Pradhan, D., Sharon, M. - Carbon nanotuhes, nanofilaments and nanobeads by thermal chemical vapor deposition process . Mater. Sci. Eng. B 96 (2002) 24—28 Mauron, R, Emmenegger, C., Zuttel, A., Nutzenadel, C., Sudan, R, Schlapbach, L. - Synthesis of oriented nanotube films by chemical vapor deposition . Carbon 40 (2002) 1339-1344... 

Lee, C., Park, J. - Growth and structure of carbon nanotubes produced by thermal chemical vapor deposition . Carbon 39 (2001) 1891-1896 Grujicic, M., Cao, G., Gersten, B. - Optimization of chemical vapor deposition process for carbon nanotubes fabrication , Appl. Surface Sci. 191 (2002) 223-239 Bonard, J., Stora, T., Salvetat, J., Maier, F., Stockli, T., Duschl, C., Forr6, L., Heer, W., Chatelain, A. - Purification and size selection of carbon nanotubes , Adv. Mater. 9(10) (1997) 827... 

High process temperatures generally not achievable by other means are possible when induction heating of a graphite susceptor is combined with the use of low conductivity high temperature insulation such as flake carbon interposed between the coil and the susceptor. Temperatures of 3000°C are routine for both batch or continuous production. Processes include purification, graphitization, chemical vapor deposition, or carbon vapor deposition to produce components for the aircraft and defense industry. Figure 7 illustrates a furnace suitable for the production of aerospace brake components in a batch operation. 

Titanium carbide may also be made by the reaction at high temperature of titanium with carbon titanium tetrachloride with organic compounds such as methane, chloroform, or poly(vinyl chloride) titanium disulfide [12039-13-3] with carbon organotitanates with carbon precursor polymers (31) and titanium tetrachloride with hydrogen and carbon monoxide. Much of this work is directed toward the production of ultrafine (<1 jim) powders. The reaction of titanium tetrachloride with a hydrocarbon-hydrogen mixture at ca 1000°C is used for the chemical vapor deposition (CVD) of thin carbide films used in wear-resistant coatings. 

Carbon Composites. Cermet friction materials tend to be heavy, thus making the brake system less energy-efficient. Compared with cermets, carbon (or graphite) is a thermally stable material of low density and reasonably high specific heat. A combination of these properties makes carbon attractive as a brake material and several companies are manufacturing carbon fiber—reinforced carbon-matrix composites, which ate used primarily for aircraft brakes and race cats (16). Carbon composites usually consist of three types of carbon carbon in the fibrous form (see Carbon fibers), carbon resulting from the controlled pyrolysis of the resin (usually phenoHc-based), and carbon from chemical vapor deposition (CVD) filling the pores (16). 

Carbon Composites. In this class of materials, carbon or graphite fibers are embedded in a carbon or graphite matrix. The matrix can be formed by two methods chemical vapor deposition (CVD) and coking. In the case of chemical vapor deposition (see Film deposition techniques) a hydrocarbon gas is introduced into a reaction chamber in which carbon formed from the decomposition of the gas condenses on the surface of carbon fibers. An alternative method is to mold a carbon fiber—resin mixture into shape and coke the resin precursor at high temperatures and then foUow with CVD. In both methods the process has to be repeated until a desired density is obtained. 

Of the many forms of carbon and graphite produced commercially, only pyrolytic graphite (8,9) is produced from the gas phase via the pyrolysis of hydrocarbons. The process for making pyrolytic graphite is referred to as the chemical vapor deposition (CVD) process. Deposition occurs on some suitable substrate, usually graphite, that is heated at high temperatures, usually in excess of 1000°C, in the presence of a hydrocarbon, eg, methane, propane, acetjiene, or benzene. 

Chemical vapor deposition (C VD) is a versatile process suitable for the manufacturing of coatings, powders, fibers, and monolithic components. With CVD, it is possible to produce most metals, many nonmetallic elements such as carbon and silicon as well as a large number of compounds including carbides, nitrides, oxides, intermetallics, and many others. This technology is now an essential factor in the manufacture of semiconductors and other electronic components, in the coating of tools, bearings, and other wear-resistant parts and in many optical, optoelectronic and corrosion applications. The market for CVD products in the U.S. and abroad is expected to reach several billions dollars by the end of the century. 

Lackey, W., Hanigofsky, J., and Freeman, G., Experimental Whisker Growth and Thermodynamic Study of the Hafnium-Carbon System for Chemical Vapor Deposition Applications, 7] Amer. Ceram. Soc., 73(6) 1593-98 (1990)... 

Brennfleck, K., Dietrich, M., Fitzer, E., andKehr, D., Chemical Vapor Deposition of Superconducting Niobium Carbonitride Films on Carbon Fibers, Eroc. 7th Int. Conf. on CVD, (T. Sedgwick andH. Lydtin, eds.), pp. 300-314, Electrochem Soc., Pennington, NJ 08534 (1979)... 

At the end of last century, a near frictionless carbon (NFC) coating was reported, which is practically hydrogen contained DLC film grown on steel and sapphire substrates using a plasma enhanced chemical vapor deposition (PECVD) system [50]. By using a ball on a disk tribo-meter, a super low friction coefficient of 0.001-0.003 between the films coated on both the ball and the disk was achieved [50]. A mechanistic model was proposed that carbon atoms on the surface are partially di-hydrogenated, resulting in the chemical inertness of the surface. Consequently, adhesive interaction becomes weak and super low friction is achieved [22],... 

Up to the present, a number of conventional film preparation methods like PVD, CVD, electro-chemical deposition, etc., have been reported to be used in synthesis of CNx films. Muhl et al. [57] reviewed the works performed worldwide, before the year 1998, on the methods and results of preparing carbon nitride hlms. They divided the preparation techniques into several sections including atmospheric-pressure chemical processes, ion-beam deposition, laser techniques, chemical vapor deposition, and reactive sputtering [57]. The methods used in succeeding research work basically did not... 

Popov, C., Zambov, L. M., Plass, M. R, and Kulisch, W., Optical, Electrical and Mechanical Properties of Nitrogen-rich Carbon Nitride Films Deposited by Inductively Coupled Plasma Chemical Vapor Deposition," Thin Solid Films, Vol. 377-378,2000, pp. 156-162. 

After lapping, the sliders will be cleaned, and then a passivation film of diamond-like carbon (DLC) will be deposited on the surfaces of sliders through chemical vapor deposition (CVD) to protect the pole area from chemical-physical corrosion and electrostatic discharge attack. Corrosion in pole areas will result in loss of read/write functions. A corrosion test was taken to examine the ability of the sliders polished by different slurries as shown in Table 6. It can be seen that the MRR change rate of the sliders polished by UFD slurry is much less than that polished by the slurry T5qre III, that is, the capability of anti-corrosion of the former is much better than that of the latter. 

Chemical vapor deposition (CVD) of carbon from propane is the main reaction in the fabrication of the C/C composites [1,2] and the C-SiC functionally graded material [3,4,5]. The carbon deposition rate from propane is high compared with those from other aliphatic hydrocarbons [4]. Propane is rapidly decomposed in the gas phase and various hydrocarbons are formed independently of the film growth in the CVD reactor. The propane concentration distribution is determined by the gas-phase kinetics. The gas-phase reaction model, in addition to the film growth reaction model, is required for the numerical simulation of the CVD reactor for designing and controlling purposes. Therefore, a compact gas-phase reaction model is preferred. The authors proposed the procedure to reduce an elementary reaction model consisting of hundreds of reactions to a compact model objectively [6]. In this study, the procedure is applied to propane pyrolysis for carbon CVD and a compact gas-phase reaction model is built by the proposed procedure and the kinetic parameters are determined from the experimental results. 

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