Condensed Matter Seminar Series
Intimate Relationship between Structural Deformation
and Properties of Carbon Nanotubes and its
Functionalized Derivatives; A first-principles study
National Institute of Standards & Technology
Thursday October 30, 1:30 pm, Room 234, Physics Building
Host: Martina Hentschel
Carbon nanotubes continue to surprise scientists with their
novel properties. Recently, we have discovered many intimate
relationships between mechanical, electronic and chemical
properties of single walled carbon nanotubes (SWNT),
that could be important in nanotechnological applications.
Using state-of-the-art first-principles total energy
calculations, we show that the mechanical deformation can
control the electronic and chemical properties of SWNTs.
The energy band gap is shown to be strongly dependent on the
curvature and on the magnitude of the applied mechanical
deformation, and the semiconducting band gap decreases and
eventually vanishes leading to metalization as a result of
increasing radial deformation. We also demonstrate that adsorption of
atoms on carbon nanotubes and associated properties can be
modified continuously and reversibly by radial deformation.
Hence, we conclude that not only the band gap but also chemical
reactions taking place on the surface of a SWNT can be engineered
through various mechanical deformations.
In addition, the effect of deformation is found to be significantly
different for the zigzag and armchair SWNT's, which may be
important in selective functionalization of nanotubes.
Finally, we discuss how the tunable electronic and chemical
properties of SWNTs via mechanical deformation can ultimately
lead to a wide variety of technological applications such as
variable metal-insulator junctions, quantum wells, catalysts,
synthesis of metal nanowires, etc.