Why do gallium clusters have a higher melting point than the bulk?

Abstract

Density functional molecular dynamical simulations have been performed on Ga${}_{17}$ and Ga${}_{13}$ clusters to understand the recently observed higher-than-bulk melting temperatures in small gallium clusters [Breaux {\em et al.}, Phys. Rev. Lett. {\bf 91}, 215508 (2003)]. The specific-heat curve, calculated with the multiple-histogram technique, shows the melting temperature to be well above the bulk melting point of 303 K, viz. around 650 K and 1400 K for Ga${}_{17}$ and Ga${}_{13}$, respectively. The higher-than-bulk melting temperatures are attributed mainly to the covalent bonding in these clusters, in contrast with the covalent-metallic bonding in the bulk.

4 pages, including 6 figures. accepted for publication in Phys. Rev. Lett

References in corpus (1)

• Thermodynamics of tin clusters

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