Vacancy formation and solid solubility in the U-Zr-N system
2010 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 406, no 3, 351-355 p.Article in journal (Refereed) Published
For the purpose of developing a nuclear fuel with enhanced thermophysical properties and better irradiation performance density functional theory calculations are used to explore UN, ZrN and (U, Zr)N. Negative deviation of ground state energy from the ideal solution model as well as energetically favourable maximal distance between substitutional metal atoms in respective nitrides indicate mutual solubility of UN and ZrN at all temperatures. Nitrogen vacancy formation energies in UN (1.81 eV) and ZrN (1.40 eV) are considerably lower than metal vacancy formation energies. A substitutional Zr atom in UN has little effect on nitrogen vacancy formation energies (similar to 1.79 eV), while U in ZrN decreases the value by similar to 0.1 eV (similar to 1.30 eV) due to elastic stress and charge density redistribution in the material. The relative distance between a substitutional metal atom and a vacancy in UN has little influence over the radially declining displacement pattern induced by the substitutional atom, while in ZrN the relaxation of atoms is governed by the position of the vacancy. The calculated vacancy formation energies indicate a lower surface energy of ZrN in comparison with UN.
Place, publisher, year, edition, pages
2010. Vol. 406, no 3, 351-355 p.
Material Property Correlations, Uranium-Nitrogen System, Advanced Nuclear-Fuels, Thermodynamic Properties, Point-Defects, Mononitride, Nitride, 1st-Principles
IdentifiersURN: urn:nbn:se:kth:diva-27681DOI: 10.1016/j.jnucmat.2010.09.006ISI: 000284750400009ScopusID: 2-s2.0-78049241493OAI: oai:DiVA.org:kth-27681DiVA: diva2:380478
FunderSwedish Research Council, 90399101
QC 201012212010-12-212010-12-202013-08-07Bibliographically approved