Enumeration of graphite carbon-bond-network defects having ring sizes ranging from 3 to 9
1984; Elsevier BV; Volume: 22; Issue: 2 Linguagem: Inglês
10.1016/0008-6223(84)90197-0
ISSN1873-3891
Autores Tópico(s)Carbon Nanotubes in Composites
ResumoA review of graph theory relevant to polycyclic conjugated hydrocarbons is provided. It is conjectured that some of the 420 pyrene isomeric structures previously enumerated can have analogs that exist as island or crystal edge carbon-bond-network defect structural units in graphite and amorphous carbon. A graphite crystal internal carbon-bond-network defect without an adjacent carbonatom-lattice-vacancy defect is composed of a number of nonhexagonal rings that are enumerated by 3r3 + 2r4 + r5 − r7 − 2r8 − 3r9 = 0 where rn is the number of rings of size n. An azupyrene structural carbon-bond-network defect is predicted to be the simplest type of graphite defect possible. Graphite carbon-bond-network defects having ring sizes of 3–9 are shown by this model to be most probable. The two-dimensional projection of the (11̄0) plane of the cubic diamond lattice structure portraying an edge dislocation or intermediate defect possesses ring sizes whose relative number are predicted by the above equation. It is suggested that two-carbon-atom-lattice-vacancies devoid of impurity atoms do not exist per se in graphite.
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