A computer simulation study of the accommodation and diffusion of He in uranium- and plutonium-doped zircon (ZrSiO4)

摘要: We report the results of an atomistic computational study He accommodation and diffusion in Pu4+- U4+-doped zircon (ZrSiO4). The He–cation potentials derived for this work give comparable accuracy to DFT calculations. have calculated structural features doped lattices as well solution energies interstitial sites perfect its these lattices. mode is influenced mainly by topological lattice, promoting site preference towards present middle c cylinder channels, whereas presence Pu4+ U4+ dopants lattice significantly affects energetics lattice. Doping causes strong local distortions, extending next nearest-neighbour atoms a radius up ∼4 A, agreement with experimental results. vicinity enhances solubility compared mechanism also affected, where can create trap along most energetically favourable pathway (0 0 1) direction, which may slow down movement direction. lower energy barriers ∼50% octahedral sites.