The melting behavior of small clusters of atoms

The melting transition of small clusters composed of 13 particles interacting via the Lennard-Jones 6-12 potential has been investigated by means of extensive Metropolis Monte Carlo simulations. The results indicate that whereas the cluster evaporates in vacuum, in a confined pore the cluster undergoes a smooth melting transition from an icosahedral microcrystal to an inhomogeneous liquid phase, with a specific heat peak centered at 39 K. No evidence was found to support the suggestion of a solid-liquid transition in vacuum at 29 K.