  Metallic nanowires are known to break into shorter fragments due to the
Rayleigh instability mechanism. This process is strongly accelerated at
elevated temperatures and can completely hinder the functioning of
nanowire-based devices like e.g. transparent conductive and flexible coatings.
At the same time, arranged gold nanodots have important applications in
electrochemical sensors. In this paper we perform a series of annealing
experiments of gold and silver nanowires and nanowire junctions at fixed
temperatures 473, 673, 873 and 973 K (200, 400, 600 and 700 {\deg}C) during a
time period of 10 minutes. We show that nanowires are especially prone to
fragmentation around junctions and crossing points even at comparatively low
temperatures. The fragmentation process is highly temperature dependent and the
junction region breaks up at a lower temperature than a single nanowire. We
develop a gold parametrization for Kinetic Monte Carlo simulations and
demonstrate the surface diffusion origin of the nanowire junction
fragmentation. We show that nanowire fragmentation starts at the junctions with
high reliability and propose that aligning nanowires in a regular grid could be
used as a technique for fabricating arrays of nanodots.
