Formation of the icosahedral C fullerene migration of single sp atoms and annihilation of sp-atom pairs.

The disappearance of sp structural defects during abundant fullerene isomer formation is considered within the framework of the atomistic mechanism with participation of carbon atoms with sp hybridization. The study is carried out using the example of the icosahedral C- fullerene formation from the appropriate C- fullerene with a 7-ring. In this case the studied atomistic mechanism includes the following stages: (1) insertion of single carbon atoms into the fullerene from carbon vapor as an sp-atom instead of or above a bond, (2) directional migration of the sp-atom positions towards the 7-ring with decrease of energy, and (3) meeting of two sp atoms near the 7-ring with annihilation of the sp-atom pair and formation of the sp structure of the C- fullerene.

Formation of carbon propeller-like molecules from starphenes under electron irradiation.

Formation of carbon propeller-like molecules (CPLMs) from starphenes on a graphene substrate under electron irradiation with about 100% yield is observed in molecular dynamics simulations using the REBO-1990EVC_CH potential and CompuTEM algorithm. A CPLM consists of three carbon atomic chains connected to the central hexagon and is formed as a result of the spontaneous breaking of bonds between zigzag atomic rows in starphene arms after hydrogen removal by electron impacts. In the absence of the substrate, the CPLM yield is slightly decreased due to sticking between forming chains, while the formation time is increased threefold.

Precise graphene cutting using a catalyst at a probe tip under an electron beam.

The method of precise cutting of 2D materials by simultaneous action of a catalyst at the tip of the scanning microscope probe and an electron beam in a high-resolution transmission electron microscope is proposed and studied using atomistic simulations by the example of graphene and a nickel catalyst. Reactive molecular dynamics simulations within the Compu-TEM approach for the description of electron impact effects show that the combination of the nickel catalyst and electron irradiation is crucial for graphene cutting. Cuts with straight edges with widths of about 1-1.

Reconstruction of Zigzag Graphene Edges: Energetics, Kinetics, and Residual Defects.

calculations are performed to study consecutive reconstruction of a zigzag graphene edge. According to the obtained energy profile along the reaction pathway, the first reconstruction step, formation of the first pentagon-heptagon pair, is the slowest one, while the growth of an already nucleated reconstructed edge domain should occur steadily at a much higher rate. Domains merge into one only in 1/4 of cases when they get in contact, while in the rest of the cases, residual defects are left.

Analysis of structural organization and interaction mechanisms of detonation nanodiamond particles in hydrosols.

Structural organization of hydrogen and oxygen functionalized nanodiamond (ND) particles in hydrosols was investigated using a cryo-TEM method. The formation of chain-like structures was observed for hydrogen functionalized NDs while oxygen functionalized NDs tend to form more compact structures. In order to understand possible interaction mechanisms between NDs in hydrosols and to explain these experimental results, first-principles calculations were performed.