  As circuitry approaches single nanometer length scales, it is important to
predict the stability of metals at these scales. The behavior of metals at
larger scales can be predicted based on the behavior of dislocations, but it is
unclear if dislocations can form and be sustained at single nanometer
dimensions. Here, we report the formation of dislocations within individual 3.9
nm Au nanocrystals under nonhydrostatic pressure in a diamond anvil cell. We
used a combination of x-ray diffraction, optical absorbance spectroscopy, and
molecular dynamics simulation to characterize the defects that are formed,
which were found to be surface-nucleated partial dislocations. These results
indicate that dislocations are still active at single nanometer length scales
and can lead to permanent plasticity.

Materials Science