Amorphous structures, carbon nitrides

McCuUoch, D. G. and Merchant, A. R., The Effect of Annealing on the Structure of Cathodic Arc Deposited Amorphous Carbon Nitride Films, Thin Solid Films, Vol. 290, 1996, pp. 99-102. 

The work on carbon nitride solids is strongly related to research on diamondlike carbon (DLC) materials [5, 6]. DLC materials are thin film amorphous metastable carbon-based solids, pure or alloyed with hydrogen, which have properties similar to that of crystalline diamond (high hardness, low friction coefficient, high resistance to wear and chemical attack). This resemblance to diamond is due to the DLC structure, which is characterized by a high fraction of highly cross-linked sp -hybridized carbon atoms. To obtain this diamond-like structure... 

C MAS-NMR spectroscopy was used to quantify the different carbon species in synthetically produced nanodiamonds.430 A 13C study has been reported to study the modification of the electronic properties of SWCNT by alkali intercalation.431,432 13C MAS-NMR data were used to study the structure of 13C-enriched SWCNT, prepared by catalytic decomposition of CH4.433 H, 13C and 15N MAS-NMR spectra of amorphous carbon nitride (a-CNx) films were consistent with sp2 hybridised nitrogen atoms in an aromatic carbon... 

Plasma decomposition of CH4 and N2 provided amorphous solids containing C, N, and H, exclusively [87], High pressure pyrolysis of tetracyanoethylene, (CN)2C=C(CN)2, gave C466N with graphitic structure [88]. Similarly, the gas phase decomposition of pyridine in the presence of chlorine at 800°C provided the carbon nitride C5N with a hexagonal sheet structure [89]. 

Martin-Gil et al. reported on the synthesis of cubic carbon nitride with the zinc blende structure by pyrolysis of N,N-diethyl-l,4-phenylene-diammonium sulphate at 800°C in an N2 atmosphere using Se02 as a catalyst [90]. The material obtained contained both an amorphous matrix and polycrystalline regions with crystallites of 5-50 nm in size. The sample as whole had a composition with 0.2 estimated using EELS (electron energy loss spectroscopy) data to be C N, with x and y between 3 and 4. The... 

Group 14. - 3.14.1 Carbon. The bonding structure in amorphous carbon nitride has been studied by H, and NMR spectroscopy. A F NMR study of paramagnetism in fluorinated graphite has been reported. Carbon-fluorine bonding has been detected in fluorine-graphite intercalation compounds by and F NMR spectroscopy. ... 

Ni3C decomposition is included in this class on the basis of Doremieux s conclusion [669] that the slow step is the combination of carbon atoms on reactant surfaces. The reaction (543—613 K) obeyed first-order [eqn. (15)] kinetics. The rate was not significantly different in nitrogen and, unlike the hydrides and nitrides, the mobile lattice constituent was not volatilized but deposited as amorphous carbon. The mechanism suggested is that carbon diffuses from within the structure to a surface where combination occurs. When carbon concentration within the crystal has been decreased sufficiently, nuclei of nickel metal are formed and thereafter reaction proceeds through boundary displacement. 

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