Preservation of C hexagons in the transformation of C allotropes

摘要

Theoretical work by Zhao et al. in (ACS Nano Lett 266(5):7226-7234, 2011) employing a novel "particle swarm methodology" has predicted the pressureinduced collapse of various, respective 1-dimensional members of the (n, 0)Cnanotube family, into their corresponding 3-dimensional network C patterns realized as the various C-based hexagonites. In particular, the so-called (6, 0) nanotubes, in which the circumference of this nanotube type is comprised of a polyacene-like belt of six benzene-like tiles, is predicted by Zhao et al. to spontaneously collapse with extreme pressure in to the parent member of the C-based hexagonite family of lattices. This prediction is supported by an independent theoretical analysis of crystallographic data obtained in a synchrotron-nanotube experiment conducted in a diamond anvil cell in 2005 byWang et al. Such nanotube-hexagonite phase transformations of C, are termed here as "hexagon-preserving-carbon-allotrope-transformations", as the hexagonal C rings are preserved in the C phase transformations. By analogy, the classical phase transformation of C-based graphene to C-based diamond is described as a "hexagonpreserving- carbon-allotrope-transformation". The details of these descriptive labels are discussed in this communication.