Sticking of carbon nanotube Y junction branches

The coalescence of branches in the Y junctions of single-wall carbon nanotubes (10 nm long) is predicted to occur when the branches approach each other under the action of a load (～10 nN) applied to their ends. A transition to the new state with parallel branches bound by molecular interactions was simulated and the energy characteristics were calculated by the molecular dynamics method. The Y junctions with parallel branches are stable at temperatures up to 2000 K. It is established that there is a threshold distance between the branch ends, below which the branches exhibit spontaneous sticking under the action of molecular attraction forces. If the branches are unloaded before this threshold distance is reached, they oscillate (acting as a nanodimensional “tuning fork”) at a frequency of ～100 GHz.     

Mechanical Characteristics of Diamond-Like Moiré Films

JETP Letters - The mechanical characteristics of diamond-like films, such as Dn21.8, Dn27.8, and Dn29.4 moiré diamanes, formed by the hydrogenation of graphene layers twisted at an angle of...     

Metallic beta-phase silicon nanowires: Structure and electronic properties

Electronic band structure and energetic stability of two types of 〈110〉 and 〈001〉 oriented silicon nanowires in β-Sn phase with the surface terminated by hydrogen atoms were studied using density functional theory. It was found that β-Sn nanowires are metastable with zero band gap against to nanowires in diamond phase. The relative energy of the studied wires tends to the energy of the bulk silicon crystal in β-Sn phase.     

Magnetic properties of C60 polymers

Magnetic properties of various C60 polymers are calculated using tight-binding molecular-dynamics and ab initio methods. Our results suggest a mechanism involving an interplay between structural defects and sp(3) hybridization to be responsible for the origin of this magnetism. The onset of magnetism is found to occur much more readily for the Rh-C60 polymeric phase with defects than for any of the other polymers, in agreement with the recent experiment. Our estimate of the magnetic moment is also in very good agreement with the value observed in experiment.     

Carbon nanotube "T Junctions": formation pathways and conductivity

Using tight-binding molecular dynamics we simulate the formation of single wall carbon nanotube T junctions via the fusing of two nanotubes. We propose energetically efficient pathways for this process in which all atoms maintain their sp(2) arrangements throughout. Recent experimental advances have greatly increased the plausibility of synthesizing T junctions as proposed in the simulations. We further report I-V characteristics of the formed junctions.     

A study of the oxidation and fluorination of single-walled carbon nanotubes by the MNDO method

This paper reports on the results of MNDO calculations of the atomic adsorption of oxygen and fluorine on the surface of armchair and zigzag single-walled carbon nanotubes with a cylindrical symmetry. The calculations are carried out within the molecular cluster and ion-incorporated covalent-periodic cluster models at the modern quantum-mechanical semiempirical MNDO level. The electronic and energy characteristics of the oxidation and fluorination processes are analyzed, and the most energetically favorable oxide structure of the (6, 6) nanotube is determined. It is found that narrow-gap tubulenes show a tendency to metallic behavior as their surface is saturated with oxygen atoms.     

Quasi-one-dimensional fullerene-nanotube composites: Structure, formation energetics, and electronic properties

Carbon nanotubes coated with close-packed C₆₀ (or C₇₀) fullerenes, which are “attached” to the nanotubes by van der Waals forces, are considered and classified as a new class of nanocomposites. Semiempirical and molecular-dynamics calculations reveal the most energetically stable systems and show that a topological (Stone-Wales) defect on a nanotube can promote a more favorable “attachment” of fullerene to the nanotube. It has been shown that the molecular interaction of the fullerene coating with the nanotube leads to a significant change in its electronic spectrum, namely, to the formation of minibands including a large number of branches associated with the lift of the degeneracy of levels of C₆₀ and to the consolidation of branches of the carbon nanotube into the Brillouin zone smaller than that in the carbon nanotube. This fact should strongly change the interaction of light with such a nanocomposite as compared to carbon nanotubes and fullerenes, which provides prospect of its application in photovoltaics.     

Wave-Packet Dynamics Study of the Transport Characteristics of Perforated Bilayer Graphene Nanoribbons

JETP Letters - The electrical conduction characteristics of perforated bilayer graphene nanoribbons are studied by the wave-packet dynamics method. The transport characteristics for typical...