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The Nanophysics team of the CNRS Photophysique moléculaire (Molecular
Photophysics) Laboratory has revealed the surprising electrical conductivity
properties of the diamond, an insulating material. For the first time,
the team imaged the surface of a diamond crystal at the atomic scale using
a tunnel effect microscope. This method could be applied to other insulating
materials and thus promote their use in designing the ultra-miniaturized
electronic devices of the future.
The study is published in Nature, October 11, 2001.
Studying the electrical conductivity
of insulating materials seems rather a wild bet. This study, carried out
at the atomic scale on a diamond surface, appears even more problematic.
The diamond is difficult to synthesize and, in the form of very pure monocrystals,
is only found in the natural state. The choice of these natural stones
meant that extremely pure, highly insulating crystals were obtained.
It might appear surprising to use a tunnel effect microscope usually intended
for conducting materials to study the electronic effects of the diamond
at the atomic scale. Using this type of microscope for an insulating material
consisted in finding and using a particular conduction band whose energy
had to be chosen with great precision. The sensitivity of this conduction
band to the atomic structure of the diamond surface was amplified by a
phenomenon of stationary waves between the point of the tunnel effect
microscope and the surface.
The nanophysics team of the Molecular Photophysics Laboratory of the CNRS
used this method to reveal the electric conduction bands sensitive to
the atomic structure. The method should be applicable to other insulating
materials, whether they are crystals other than the diamond, molecular
films or polymers.
These results open new horizons for nano-electronics, or atomic-scale
electronics. Insulating surfaces are essential for the nano-electronics
of the future. The diamond is the ideal material, better than other insulators,
since it has exceptional properties of hardness, stability and thermal
dissipation. The CNRS team's discovery shows the way to a veritable diamond
technology at the atomic scale.
Reference: Atomic scale imaging of insulating diamond through
resonant electron injection, K. Bobrov, A.J. Mayne and G. Dujardin, Nature,
October 11, 2001.
Researcher
contact:
Gérald Dujardin
Laboratoire de photophysique moléculaire (CNRS)
Tel: + 33 1 69 15 77 13
E-mail: gerald.dujardin@ppm.u-psud.fr
Mathematics
and Physical Science Department contact:
Frédérique Laubenheimer
Tel: + 33 1 44 96 42 63
E-mail: frederique.laubenheimer@cnrs-dir.fr
Press contact
:
Carine Noël
Tel: + 33 1 44 96 46 06
E-mail: carine.noel@cnrs-dir.fr
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