Combining mesoscale thermal transport and x-ray diffraction measurements to characterize early-stage evolution of irradiation-induced defects in ceramics

Phase and defect evolution in uranium-nitrogen-oxygen system under irradiation

“…The efficiency of energy generation and utilization systems depends on material property changes influenced by microstructure evolution under extreme operating conditions. Particularly in environment where materials are subjected to a flux of energetic neutrons and charged particles, degradation of mechanical properties [1,2], corrosion/oxidation resistance [3][4][5][6][7], and thermal conductivity [8][9][10] have been associated with defect generation, and compositional redistribution in the microstructure. Energetic particles can knock atoms out of their lattice site and create point defects (vacancies, interstitials).…”

Structural dynamics of Schottky and Frenkel defects in ThO2: a density-functional theory study

“…10. To allow for comparison between systems, we have normalized the functions by (3n a ) 2 , which is folded into the P l term in eqn (19). Peaks in the N 2 (u) at low frequencies are likely to indicate an enhanced broadening of the acoustic modes, which as noted above typically contribute the most to the thermal conductivity, leading to shorter lifetimes and suppressing the heat transport.…”

“…15 and 16) and UO 2 . [17][18][19] While a variety of point defects and defect clusters can be found in uorite structures, Schottky and Frenkel defects are simple, charge-neutral defects. These will both be produced under reactor operating conditions, and are likely to have an impact on the thermal conductivity, 15,19 but unravelling this at the nanoscale requires computational approaches since disentangling the effects of specic defects using experimental approaches is challenging and currently limited.…”

Improving empirical interatomic potentials for predicting thermophysical properties by using an irreducible derivatives approach: The case of thorium dioxide

“…While EIPs determine the atomic interactions in MD, effective methods are needed for parametrization of EIPs in order to improve the accuracy of their predictions of transport properties. One particular application of interest to this study is understanding the impact of irradiation-induced defects on the thermal transport of nuclear fuels [12][13][14][15]. Another important aspect of EIPs is their utilization in estimating the defect formation and migration energies necessary for understanding the evolution of microstructures under bombardment by energetic particles [14][15][16][17].…”