journal article·2019-03Open access

Shining a light on amorphous U2O7: A computational approach to understanding amorphous uranium materials

Ashley E. Shields, Andrew J. Miskowiec, J.L. Niedziela, Marie C. Kirkegaard, Ketan Maheshwari, Michael W. Ambrogio, Roger J. Kapsimalis, Brian B. Anderson

Optical Materials· Volume 89

Abstract

Abstract Mixed-phase and low-symmetry systems are widely observed among uranium oxide materials. Amorphous-U2O7 forms during the calcination of studtite, a uranyl peroxide mineral. Using a genetic algorithm search for stable crystalline phases, we have identified a potentially stable phase of U2O7 that shares structural features with experimentally observed amorphous U2O7 samples. The crystalline structure is expected to undergo a solid–solid phase change around 12 GPa.
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Research context

OpenAlex topics: Radioactive element chemistry and processing · Nuclear materials and radiation effects · Nuclear Materials and Properties

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

References (18)

Show source-provided references
1. Energetics of metastudtite and implications for nuclear waste alteration10.1073/pnas.1421144111 ↗
2. Structure and reactivity of X-ray amorphous uranyl peroxide, U2O710.1021/acs.inorgchem.6b00017 ↗
3. Nuclear forensics investigation of morphological signatures in the thermal decomposition of uranyl peroxide10.1016/j.talanta.2017.08.020 ↗
4. Giant pressure-induced volume collapse in the pyrite mineral MnS210.1073/pnas.1318543111 ↗
5. New metastable phases in an oxyborate compound obtained by an evolutionary algorithm and density functional theory10.1016/j.jmmm.2017.03.061 ↗
6. Stability of U5Si4 phase in U–Si system: crystal structure prediction and phonon properties using first-principles calculations10.1016/j.jnucmat.2018.08.026 ↗
7. Crystal structure prediction using ab initio evolutionary techniques: principles and applications10.1063/1.2210932 ↗
8. How evolutionary crystal structure prediction works—and why10.1021/ar1001318 ↗
9. Ab initio molecular-dynamics simulation of the liquid-metal–amorphous-semiconductor transition in germanium10.1103/PhysRevB.49.14251 ↗
10. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set10.1016/0927-0256(96)00008-0 ↗
11. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set10.1103/PhysRevB.54.11169 ↗
12. From ultrasoft pseudopotentials to the projector augmented-wave method10.1103/PhysRevB.59.1758 ↗
13. Restoring the density-gradient expansion for exchange in solids and surfaces10.1103/PhysRevLett.100.136406 ↗
14. Electron-energy-loss spectra and the structural stability of nickel oxide: an LSDA+U study10.1103/PhysRevB.57.1505 ↗
15. Grain boundaries in uranium dioxide: scanning electron microscopy experiments and atomistic simulations10.1111/j.1551-2916.2010.04295.x ↗
16. Density functional theory calculations of defective UO2 at U3O7 stoichiometry10.1016/j.jnucmat.2015.10.006 ↗
17. DFT+U study of the structures and properties of the actinide dioxides10.1016/j.jnucmat.2017.05.025 ↗
18. Hidden magnetic order in plutonium dioxide nuclear fuel10.1039/C8CP03583K ↗