https://doi.org/10.1140/epjb/e2005-00026-6
Melting and evaporation transitions in small Al clusters: canonical Monte-Carlo simulations
Institut für Theorie der Kondensierten Materie, Universität
Karlsruhe, 76128 Karlsruhe, Germany
Corresponding author: a werner@tkm.uni-karlsruhe.de
Received:
12
August
2004
Revised:
30
November
2004
Published online:
11
February
2005
A dimer of bound atoms cannot melt, only dissociate. Bulk
metals show a well defined first order transition between their
solid and liquid phases. The appearance of the melting transition is
explored for increasing clusters sizes via the signatures in the
specific heat and the root mean square of the bond lengths 
(Berry parameter) by means of Monte-Carlo
simulations of Al clusters modelled by Gupta potentials. Clear
signatures of a melting transition appear for 
atoms. Closed-shell effects are shown for clusters with up to 56 atoms. The melting transition is compared in detail with the
dissociation transition, which induces a second and possibly much
larger local maximum in the specific heat at higher
temperatures. Larger clusters are shown to fragment into dimers and
trimers, which in turn dissociate at higher temperatures.
PACS: 61.46.+w – Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals / 65.80.+n – Thermal properties of small particles, nanocrystals, nanotubes
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005
