QUANTUM CHEMICAL INVESTIGATIONS OF THE GROWTH MODELS OF SINGLE WALL CARBON NANOTUBES ON POLYHEN RINGS, FULLERENES AND DIAMOND SURFACE

摘要

Quantum-mechanical MNDO calculations were performed for models of the growth of achiral carbon nanotubes from polyene rings of the cis and trans types, fullerene and diamond (111) surface. Several variants of the growth of nanotubes (by absorption of dimers or trimers or a mixed set of species) were considered. A comparison of the obtained characteristics, in particular, the total energies of sequential absorption, allowed several conclusions to be drawn on the possibility of growth of cyclic nanotubes of the (n, n) and (n, 0) types from polyene rings by absorption of carbon dimers as the most probable process. The orbital-stoihiometric cluster (OSC) model in the framework of quantum chemical MNDO-scheme has been applied to simulate the diamond nanocluster in order to study carbon nanotube generation process on diamond (111) surface. The comparison of the received characteristics of processes, in particular adsorption energy, has shown, that most favourable process is carbon monomer sorption on a pure diamond (111) surface. Processes of nanotube origin on surface quantum dots, which have been simulated by adsorbed Li, Na, K, Be, and H atoms, have shown high efficiency of nanotube growth: all of them proceed without energy barriers.