Showing 91 results for Author: Ashley E. Shields
Aug, 2025
Journal
Recent computational work evaluated the phase stability of UCo2 and UNi2 in the C14, C15, and C36 Laves phases and reported their computationally determined phonon density of states. To corroborate these computational findings, we report the experimentally determined phonon density of states for UCo2 and UNi2 using inelastic neutron scattering at the wide angular-range cho…
Jul, 2025
Journal
We present neutron diffraction, electronic structure calculations, and optical vibrational spectroscopic characterization of hydronium uranyl phosphate (HUP), the synthetic analog of chernikovite ((H3O)(UO2)(PO4)·3H2O) to gain insight into structural features of the hydronium cation in the solid state. HUP crystallizes in P21/c instead of previously reported P4/ncc1 at roo…
Jun, 2025
ORNL Report
Apr, 2025
ORNL Report
Mar, 2025
Journal
α-UO3 is a common intermediate compound found in the nuclear fuel cycle, yet the exact crystal structure of this material has long been debated. Inconsistent computational and experimental data in previous works has led to varying conclusions between authors. To ensure the validity of our results in this work, the structural and spectroscopic signatures of pure phase α-UO3…
Feb, 2025
Journal
Nuclear fuel produced with trace amounts of transition metal additives is of potential interest for introducing intentional signatures for accelerating nuclear forensics. In this work, we investigate the effects on microstructure, grain size, crystal structure, and stoichiometry when trace amounts of Fe in the form of Fe2O3 are added to UO2. Sintering of compacts with diff…