Modeling of point defects and rare gas incorporation in uranium mono-carbide

A. Chartier (1) , L. van Brutzel (1)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)

An embedded atom method (EAM) potential has been established for uranium mono-carbide. This EAM potential was fitted on structural properties of metallic uranium and uranium mono-carbide. The formation energies of point defects, as well as activation energies for self migration, have been evaluated in order to cross-check the suitability of the potential. Assuming that the carbon vacancies are the main defects in uranium mono-carbide compounds, the migration paths and energies are consistent with experimental data selected by Catlow[C.R.A. Catlow, J. Nucl. Mater. 60 (1976) 151]. The insertion and migration energies for He, Kr and Xe have also been evaluated with available inter-atomic potentials [H.H. Andersen, P. Sigmund, Nucl. Instr. and Meth. B 38 (1965) 238]. Results show that the most stable defect configuration for rare gases is within uranium vacancies. The migration energy of an interstitial Xe is 0.5 eV, in agreement with the experimental value of 0.5 eV [Hj. Matzke, Science of advanced LMFBR fuels, Solid State Physics, Chemistry and Technology of Carbides, Nitrides and Carbonitrides of Uranium and Plutonium, North-Holland, 1986].

Mots clés: Uranium carbide; EAM potential; Molecular dynamics; Point defects; Migration; Rare gases

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

A. Chartier, L. van Brutzel. Modeling of point defects and rare gas incorporation in uranium mono-carbide. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2007, 255 (1), pp.146-150. ⟨10.1016/j.nimb.2006.11.017⟩. ⟨cea-02513468⟩