Free energy of small face centred cubic clusters of atoms

Abstract

An atomistic calculation of the free energies of small clusters having 3 to 87 atoms has been carried out. The free energies of the most probable configurations can be described by a simple analytical expression and differ from the predictions of the classical capillarity model. We also examine the importance of considering all possible configurations of a cluster when computing thermodynamic properties. Nucleation rates are calculated from the exact thermodynamic properties and compared with the predictions of classical nucleation theory. Exact rates differ from the classical rates by factors from 10^–2 to 10⁷. The correction depends strongly on both supersaturation and temperature.