Using tools like Density Functional Theory and Molecular Dynamics to calculate the properties of materials in extreme environments.
Uranium dioxide has a complicated
magnetic structure (collinear on left and non-collinear on right) as well as a
distortion in the oxygen sublattice.
Nuclear fuels like uranium dioxide (UO2), when undergoing fission, produce other elements, such as xenon. Xenon atoms tend to aggregate into bubbles in UO2 and degrade the properties of the fuel as well as cause a physical swelling. We seek to understand the beginnings of xenon bubble formation in UO2, using ab initio calculations.
Noble gas atoms in the interstitial
sites of UO2 induce strain, indicated by pink areas
(left). The strain can be relieved by creating a cavity for a bubble to form
(right). There will be a point at which the savings of relieving the strain
energy of the dispersed noble gas atoms outweigh the cost of creating the
bubble to contain those atoms. From my DFT+U calculations, the number of xenon
atoms needed for the bubble to be energetically favored is one.
BS. Materials Science and Engineering, Purdue University, 2007
A. Thompson, C. Wolverton, First-principles study of noble gas impurities and defects in UO2
, Physical Review B 84
B. Meredig, A. Thompson, H.A. Hansen, C. Wolverton, (2010) Method for locating low-energy solutions within DFT+U
, Physical Review B 82
and Engineering 17 015007
A. Thompson, A Strachan, (2010) Complex martensitic nanostructure in Zr nanowires: A molecular dynamics study, Physical Review B 81
A. Thompson, A. Strachan,
(2009) Coarse grain modeling of spall failure in molecular crystals: role of intra-molecular degrees of freedom, Modeling Simulation in Materials Science