Abstract Submitted to the NANOTUBE-99 Workshop:

This paper follows the communication entitled "Simulation of STM images of carbon nanotubes: I. Basic principles and illustrations". This communication is intended to present the theoretical aspects of the STM images of various carbon nanotubes species. We use a tight-binding formulation of the tunnel current (Phys. Rev. Lett. 81, 5888 (1998)). This formalism is simple enough to be used routinely and efficiently on different geometries and give accurate results as compare to ab initio STM simulations. Starting from perfect nanotubes (i.e. in which the sp2 network forms a perfect hexagonal lattice), we emphasize the effect of topological defects, namely pentagons, heptagons and octogons. We investigate the influence of the ending caps and the "pentagon-heptagon" pair defects which generate conical sections and make possible to connect two different nanotubes. Some particular situations are also studied: twisted carbon nanotubes, Stone-Wales defected tubules and small polygonized tori. STS computations on finite size nanotubes are also performed in order to reproduce and understand recent experimental data. On the other hand, images of deformed hexagonal lattices or "ghost" images can take place depending on the tip geometry. In summary, this communication is an occasion to stress out the fact that unexpected geometrical and electronic effects take place and make the interpretation of STM images a task to be taken carefully.

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