The formation energies of small HenVm clusters (where n and m denoted the numbers of He atoms and vacancies, respectively) in Pu were calculated with molecular dynamics simulations using the embedded atom method potential, the Morse potential and the Lennard-Jones potential for describing the interactions of Pu-Pu, Pu-He and He-He, respectively. The binding energies of an interstitial He atom, an isolated vacancy and a self-interstitial Pu atom to a HenVm cluster were also obtained from the calculated formation energies of the clusters. All the binding energies mainly depended upon the He-vacancy ratio (n /m) of clusters rather than the clusters size. With the increase of the n /m ratio, the binding energies of a He atom and a Pu atom to a HenVm cluster decreased with the ratio, and the binding energy of a vacancy to a HenVm cluster increased. Helium atoms acted as a catalyst for the formation of HenVm clusters.

Interaction between Helium and Vacancy in Plutonium by Embedded Atom Method. B.Ao, X.Wang, W.Hu, J.Yang: Physica Status Solidi B, 2008, 245[8], 1493-7