EFFECT OF SHAPE ON PHASE-TRANSITION TEMPERATURE OF CLUSTERS

The effect of shape on the melting transition in enclosed anisotropic clusters is considered. A simple thermodynamic model demonstrates a dependence of the melting temperature on the surface to volume ratio of the cluster. Molecular dynamic simulations are applied to an embedded cluster of atoms interacting through a Lennard-Jones potential. The simulations illustrate the existence of a wide liquid layer below the melting point and are used to calculate the melting temperature in the case of an ellipsoidal cavity, a double droplet and a finite cylinder. In the cases considered the melting temperature follows the dependence on the surface to volume ratio if the shape of the cavity does not depart too far from spherical or cylindrical symmetry.