  The thermal stabilization of thin gold nanowires with a diameter of about 2
nm by surfactants is investigated by means of classical molecular dynamics
simulations. While the well-known melting point depression leads to a much
lower melting of gold nanowires compared to bulk gold, coating the nanowires
with surfactants can reverse this, given that the attractive interaction
between surfactant molecules and gold atoms lies beyond a certain threshold. It
is found that the melting process of coated nanowires is dominated by surface
instability patterns, whereas the melting behaviour of gold nanowires in vacuum
is dominated by the greater mobility of atoms with lower coordination numbers
that are located at edges and corners. The suppression of the melting by
surfactants is explained by the isotropic pressure acting on the gold surface
(due to the attractive interaction) which successfully suppresses
large-amplitude thermal motions of the gold atoms. (Note that this is a
pre-peer-reviewed version which has been submitted to Nanoscale.)
