Physicists Discover Gold Can Be Magnetic on the Nanoscale
Date: Saturday, March 08, 2008 @ 18:48:31 UTC
Topic: Science
Atlanta (February 28, 2008) —Physicists at the Georgia
Institute of Technology have made two important findings regarding gold
on the nanoscale. They found that applying an electrical field on a
surface-supported gold nanocluster changes its structure from a
three-dimensional one to a planar flat structure. In another paper,
they relate their discovery that gold in this size regime can be made
magnetic through oxygenation of gold nanowires. They also found that up
to a certain length, oxygenated gold nanowires behave as a conducting
metal, but beyond that, they become insulators. This marks the first
time on the nanoscale that such a metal-to-insulation transition has
been found on the nanoscale. Both findings are important predictions
that could some day be implemented as control parameters governing the
chemical and physical material properties employed in nanotechnology.
The researchers focused their theoretical investigations on gold
nanostructures because of the well known chemical inertness of gold in
the bulk form, allowing one to maintain samples with minimal influence
on the environment.
“However, we again find that small is different,” said Uzi Landman,
Regents’ and Institute Professor, holder of the F.E. Callaway Chair,
and director of the Center for Computational Materials Science,
repeating a phrase that he coined and has used often for close to two
decades. “On the nanoscale, even gold becomes a potent catalyst,
exhibiting new and surprising, chemical, mechanical, electrical and
magnetic behavior, which could not have been extrapolated or predicted
on the basis of our knowledge about this substance in the bulk form.
Some of these systems may find technological uses in nanocatalysis and
as chemical and electrical sensors,” Landman added. ...
More: http://www.gatech.edu/newsroom/release.html?id=1738
|
|