IWEPNM99, Kirchberg, Research Lecture given by L. P. Biro

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The use of computer simulation to investigate tip
shape and point contact effects during
scanning tunneling microscopy of supported
nanostructures


G\'eza I. M\'ark, L\'aszl\'o P. Bir\'o, J\'ozsef Gyulai,
Paul A. Thiry, Philippe Lambin

A recently developed computer code\cite{ref:CSO1998}
is used to investigate
effects which may arise during the STM investigation of
supported nanostructures, like carbon nanotubes.  The effects of
tip geometry and point contact imaging are studied.
The calculations show that while the magnitude of the
tunnel current is determined by the tip-nanotube tunnel gap,
the asymmetry of the tip -/+ current is influenced
by the nanotube-support tunnel gap.
The results
obtained from simulation are compared with experimental
data.
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