Chemical diamond films

CHEMISTRY OF SUPERCONDUCTOR MATERIALS edited by Terrell A. Vanderah CONTACTS TO SEMICONDUCTORS edited by Leonard J. Brillson DIAMOND CHEMICAL VAPOR DEPOSITION by Huimin Liu and David S. Dandy DIAMOND FILMS AND COATINGS edited by Robert F. Davis... 

Ohtake, N., and Yashikawa, M., Diamond Film Preparation by Arc Discharge Plasma Jet Chemical Vapor Deposition in the Methane Atmosphere, / Electrochem. Soc., 137(2) 717-722(1990)... 

Chapter 1 contains a review of carbon materials, and emphasizes the structure and chemical bonding in the various forms of carbon, including the four allotropes diamond, graphite, carbynes, and the fullerenes. In addition, amorphous carbon and diamond films, carbon nanoparticles, and engineered carbons are discussed. The most recently discovered allotrope of carbon, i.e., the fullerenes, along with carbon nanotubes, are more fully discussed in Chapter 2, where their structure-property relations are reviewed in the context of advanced technologies for carbon based materials. The synthesis, structure, and properties of the fullerenes and... 

At temperatures around 600°C and extremely low pressures, methane will decompose and deposit a thin film of carbon, in the form of diamond, on a surface. The process, known as chemical vapour deposition, or CVD, can be used to coat a wide variety of surfaces. The hardness of this diamond film can be used for applications that require non-scratch surfaces such as cookware, eyeglasses, and razor blades. 

Fullerenes have potential applications in the preparation of carbon support catalyts and diamond films. They have high electrical conductivity and chemical reactivity. 

FIGURE 3.10 (a) Chemical-vapour deposition reactor (b) cross section of a 100 pm-thick CVD diamond film grown by DC arc jet. The columnar nature of the growth is evident, as is the increase in film quality and grain size with growth time. (Courtesy of Dr. Paul May and Prof. Mike Ashfold, Bristol University.)... 

Researchers are now seeking practical ways to fluorinate the surfaces of diamond films, as the resulting surfaces are expected to have very low coefficients of friction (cf. non stick polytetrafluoroethylene or Teflon, Section 12.3) and hence have applications in low-friction tools. Direct flu-orination with elemental fluorine is impractical, but photodecomposition of fluoroalkyl iodides chemically absorbed on the diamond surface looks promising.4... 

The boron-doped diamond film electrode is the newest of the voltammetric indicator electrodes. It is promising because of its high chemical stability, low background currents, and wide potential windows (high overpoten-... 

Two principal classes of diamond film deposition have been developed (I) PACVD (plasma-assisted chemical vapor deposition) and (2) IBED (ion-beam-enhanced deposition). 

Figure 2. The low-loss plasmon spectrum of a) low pressure chemical vapour deposition diamond films b) diamond residue from the Allende carbonacious chondrite.

Starting with the paper [11] and until recent years, the studies in diamond electrochemistry were concerned entirely with diamond films grown by the chemical vapor... 

Figure 1. Connectivities and principle bonding properties of carbon. From top to bottom connectivity, chemical bonding representation, distribution of n electrons, hybridization symbol, bond length, orientation of the n bonds relative to the carbon skeleton. The spectra represent polarization-dependent carbon 1 s XAS data for sp2 and sp3 carbons. The angles denote the orientation of the E vector of the incident light relative to the surface normal of the oriented sample. The assignment of the spectral regions is given and was deduced from the angular dependence of the intensities of each feature. The graphite impurity in the CVD diamond film is less than 0.1 monolayers.

Furthermore, it has been proved that direct oxidation can happen on the diamond film electrode before the oxygen gas evolution potential (Zhi et al. 2003). Direct oxidation takes place, accompanying with the adsorption of chemical molecules on the diamond electrode surface. An as-grown diamond film with high hydrogen coverage is inert to adsorption of polar molecules (Vinokur, Miller et al. 1996 Yano... 

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