Topological and Energetic Conditions for Lithographic Production of Carbon Nanotubes from Graphene

Abstract

Density Functional Based Tight-Binding (DFTB) molecular dynamics (MD) simulations were performed for producing carbon nanotubes from graphene nanoribbons. The constant temperature simulations were controlled with the help of Nosé-Hoover thermostat. In our systematic study we obtained critical curvature energies and determined topological conditions for nanotube production from two parallel graphene nanoribbons. We obtained linear relationship between the curvature energy and the square of the curvature.

Self-organizing Behavior of Y-junctions of Graphene Nanoribbons

“…In our previous publication [24,32] we have studied the self-organized formation of nanotubes from graphene ribbons in molecular dynamics simulation. The distance between the two initial ribbons was 0.35 nm.…”

“…In every case, we started from a model consisting of two parallel graphene ribbons [24]. The distance of the ribbons was equal to the equilibrium distance between the layers of the graphite crystals: 3.35 Å (in case of the zigzag models, containing the substrates as well, we deviated from this, this will be indicated in the right place).…”

“…The dimensions have been chosen in order to conform to the earlier research results obtained for the straight carbon nanotubes [24]: Critical ribbon width, derived from curvature energy, distinguishes cases of low and high probability of perfect In case of the models of the Y-junctions we examined the critical ribbon width range. For the molecular dynamics simulation experiments we used models of three different widths from the range around critical width.…”

“…The production of nanotubes from two parallel nanoribbons is not a trivial task. First the possibility was published [22][23], and after that the topological and energetic conditions for obtaining perfect tubes were published [24]. It is well known that the nanotubes have very interesting electronic and mechanical properties.…”

Position Sensitivity Study in Molecular Dynamics Simulations of Self-Organized Development of 3D Nanostructures

“…Growing carbon nanotubes from two, parallel graphene ribbons is far from being a trivial task. Although the possibility has already been demonstrated using molecular dynamics (MD) simulation [25][26], and later it has also been demonstrated by MD simulation that a defect-free nanotube structure can be formed only if the necessary topological and energetic conditions are met [36]. This article investigates the sensitivity of defect-free fusion of parallel graphene ribbons into straight carbon nanotubes depending on the position of the edges of zigzag graphene ribbons.…”