Multi-scale model for point defects behaviour in uranium mononitride

International Conference for Young Scientists, Specialists, and Postgraduates on Nuclear Reactor Physics 2016

Starikov, S.^1 ; Kuksin, A.^1 ; Smirnova, D.^1

Joint Institute for High Temperatures, Russian Academy of Sciences Nuclear Safety Institute, Russian Academy of Sciences, Russia^1

关键词: Ab initio calculations;    Finite temperatures;    Interatomic potential;    Molecular dynamics simulations;    Multi-scale approaches;    Multi-scale Modeling;    Non-stoichiometric;    Thermodynamic model;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/781/1/012044/pdf
DOI  :  10.1088/1742-6596/781/1/012044

来源: IOP

【 摘 要 】

A multiscale approach was used to study the properties of point defects in uranium mononitride (UN). In this work we used combination of several methods: ab initio calculations; molecular dynamics simulations with a new interatomic potential; thermodynamic model. Density functional theory (DFT) calculations are used for fitting of the parameters of the angular-dependent interatomic potential, as well as for evaluation of the defects formation and migration energies. Molecular dynamics (MD) simulations are applied to analyze what migration/formation mechanisms are activated at finite temperatures and to calculate diffusion coefficients of point defects. The thermodynamic model for description of concentrations and diffusivities for point defects in non-stoichiometric UN1+xis proposed.