Onions diamond synthesis

Kuznetsov V.I. and Butenko Yu.V. (2003) Synthesis and properties of nanostructured carbon materials nano-diamond, onion-like carbon and carbon nanotubes. In Proceedings of NATO Advanced Research Workshop on Nanostructured Materials and Coatings for Biomedical and Sensor Applications , 4-8 August 2002. Eds. Gogotsi Y.G. and Uvarova I.V. V. 102, IOS Press, p. 187-202. 

Kuznetsov, V.L. and Butenko, Y.V. (2005) Nanodiamond Graphitization and Properties of Onion-like Carbon, in Synthesis, Properties and Applications of Ultrananocrystalline Diamond, NATO Science Series, vol. 192 (eds D.M. Gruen,... 

Feynman s vision of miniaturization and the Drexler-versus-Smalley debate on feasibility of mechanosynthetic reactions using molecular assemblers were discussed. Fullerenes are the third allotropic form of carbon. Soccer-ball-structured Cgo with a surface filled with hexagons and pentagons satisfies Euler s law. Howard patented the first generation combustion synthesis method for fullerene production. The projected price of the fullerenes has decreased from 165,000 per kg to 200 per kg in the second-generation process. Fullerenes can also be synthesized using chemical methods, a supercritical extraction method, and the electric arc process. Applications of fullerenes include high temperature superconductors, bucky onion catalysts, advanced composites and electromechanical systems, synthetic diamonds. 

In contrast to the spherical carbon onions observed in the first experiments by Ugarte, OLC particles were subsequently produced with polyhedral facets, more closely matching the polyhedral structures predicted from the consideration of nested fullerene structures described above. These polyhedral onion-like particles were synthesized by vacuum heat treatment of carbon sooF and diamond nanoparticles." Figure 10.5 presents HRTEM images of the polyhedral OLC particles produced in the experiments of Kuznetsov et al. The range of synthesis methods available has led to the production of different types of OLC. In addition to their shape, such carbon onions can be characterized by other parameters, such as the number of concentric shells, the spacing between adjacent shells, the size of the innermost shell, and the presence of different types of defects. 

Figure 3.6 Schematic of the synthesis apparatus used for the carbon onion synthesis. Two different crucibles were used to obtain carbon onions a graphite crucible (carbon onions with diamond core) and a tantalum boat...

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