First-principles calculation on free energy of precipitate nucleation

A slight modification of the nucleation theory enables reliable calculations of cluster free energies of precipitate nucleation. This method divides the free energy into the cluster energy and entropy terms. The former, consisting of the enthalpy of driving force and the interface energy, is precisely calculated by first-principles calculations. The latter, which is entropy loss from scattered atoms condensing into a cluster, is estimated by the ideal solution model. Model calculations have been performed for an Fe–Cu alloy, Ni added Fe–Cu alloy, and vacancy behavior around Cu clusters.