journal article·2017-07Open access

Structure and bulk modulus of Ln-doped UO2 (Ln = La, Nd) at high pressure

Dylan R. Rittman, Sulgiye Park, Cameron L. Tracy, Lei Zhang, Raul I. Palomares, Maik Lang, Alexandra Navrotsky, Wendy L. Mao, Rodney C. Ewing

Abstract

Abstract The structure of lanthanide-doped uranium dioxide, LnxU1-xO2-0.5x+y (Ln = La, Nd), was investigated at pressures up to ∼50–55 GPa. Samples were synthesized with different lanthanides at different concentrations (x ∼ 0.2 and 0.5), and all were slightly hyperstoichiometric (y ∼ 0.25–0.4). In situ high-pressure synchrotron X-ray diffraction was used to investigate their high-pressure phase behavior and determine their bulk moduli. All samples underwent a fluorite-to-cotunnite phase transformation with increasing pressure. The pressure of the phase transformation increased with increasing hyperstoichiometry, which is consistent with results from previous computational simulations. Bulk moduli are inversely proportional to both the ionic radius of the lanthanide and its concentration, as quantified using a weighted cationic radius ratio. This trend was found to be consistent with the behavior of other elastic properties measured for Ln-doped UO2, such as Young's modulus.
Source: openaire · Quality: candidate unverified · Source record ↗

Research context

OpenAlex topics: Nuclear Materials and Properties · High-pressure geophysics and materials · Nuclear materials and radiation effects

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

References (44)

Show source-provided references
1. Fission-product yields from neutron-induced fission10.1016/0092-640X(77)90023-7 ↗
2. Mechanistic interpretations of UO2 oxidation10.1016/S0022-3115(97)00291-2 ↗
3. Microstructural features of SIMFUEL—simulated high-burnup UO2-based nuclear fuel10.1016/0022-3115(91)90455-G ↗
4. “Thermal conductivity of SIMFUEL10.1016/0022-3115(92)90471-V ↗
5. Radiation damage-enhanced dissolution of UO2 in water10.1016/0022-3115(92)90080-5 ↗
6. Thermal conductivity of UO2+x and U4O9−y10.1016/j.jnucmat.2013.07.063 ↗
7. Molecular dynamics simulation of thermal transport in UO2 containing uranium, oxygen, and fission-product defects10.1103/PhysRevApplied.6.044015 ↗
8. Thermodynamic modeling of the (U,La)O2±x solid solution phase10.1016/j.jnucmat.2012.09.009 ↗
9. Charge distribution and oxygen diffusion in hyperstoichiometric uranium dioxide UO2+x (x≤0.25)10.1016/j.jnucmat.2011.09.003 ↗
10. Average structure and local configuration of excess oxygen in UO2+x10.1038/srep04216 ↗
11. The defect structure of hyper-stoichiometric uranium dioxide10.1107/S0567739478000157 ↗
12. Thermodynamics of fission products in UO2±x10.1088/0953-8984/21/43/435602 ↗
13. X-ray powder diffraction study of the high pressure behaviour of uranium dioxide10.1051/jphyslet:01982004306017100 ↗
14. Behavior of actinide dioxides under pressure: UO2 and ThO210.1103/PhysRevB.70.014113 ↗
15. Electronic structure and stability of hyperstoichiometric UO2+x under pressure10.1103/PhysRevB.88.024109 ↗
16. Elastic properties of UO2 at high pressure10.1063/1.322438 ↗
17. Elastic constants, phonon density of states, and thermal properties of UO210.1103/PhysRevB.84.014116 ↗
18. Phonon spectrum, thermodynamic properties, and pressure-temperature phase diagram of uranium dioxide10.1103/PhysRevB.88.104107 ↗
19. Elastic constants of single crystal UO2 at 25°C10.1016/0022-3115(65)90089-9 ↗
20. Multidimensional multiphysics simulation of nuclear fuel behavior10.1016/j.jnucmat.2012.01.012 ↗
21. Materials research on inert matrices: a screening study10.1016/S0022-3115(99)00062-8 ↗
22. Nanoindentation studies of UO2 and (U,Ce)O210.1016/j.jallcom.2004.03.084 ↗
23. Effect of Nd and Pr addition on the thermal and mechanical properties of (U,Ce)O210.1016/j.jnucmat.2009.01.011 ↗
24. Study of the thermodynamic properties of (U,Ce)O210.1016/S0022-3115(97)00076-7 ↗
25. Mechanical properties of (U,Ce)O2 with and without Nd or Zr10.1016/S0925-8388(01)01557-2 ↗
26. Thermal and mechanical properties of (U,Er)O210.1016/j.jnucmat.2009.01.016 ↗
27. Thermochemistry of rare earth doped uranium oxides LnxU1−xO2−0.5x+y (Ln= La, Y, Nd)10.1016/j.jnucmat.2015.06.059 ↗
28. Calibration of the ruby pressure gauge to 800 kbar under quasi-hydrostatic conditions10.1029/JB091iB05p04673 ↗
29. Hydrostatic limits of 11 pressure transmitting media10.1088/0022-3727/42/7/075413 ↗
30. DIOPTAS: a program for reduction of two-dimensional X-ray diffraction data and data exploration10.1080/08957959.2015.1059835 ↗
31. MAUD (material analysis using diffraction): a user friendly Java program for Rietveld texture analysis and more
32. Structural characterization of natural UO2 at pressures up to 82 GPa and temperatures up to 2200 K10.2138/am.2008.2735 ↗
33. What is the actual local crystalline structure of uranium dioxide, UO2? A new perspective for the most used nuclear fuel10.1021/acs.inorgchem.6b02111 ↗
34. Probing disorder in isometric pyrochlore and related complex oxides10.1038/nmat4581 ↗
35. Metallographic determination of the UO2-U4O9 phase diagram10.1016/0022-3115(60)90038-6 ↗
36. X-Ray and density study of nonstoichiometry in uranium oxides10.1021/ba-1964-0039.ch005 ↗
37. High pressure phase transitions and compressibilities of Er2Zr2O7 and Ho2Zr2O710.1063/1.2830832 ↗
38. Finite elastic strain of cubic crystals10.1103/PhysRev.71.809 ↗
39. Structural behavior of α-uranium with pressures to 100 GPa10.1103/PhysRevB.67.134102 ↗
40. High-pressure synchrotron X-ray diffraction study of the pyrochlores: Ho2Ti2O7, Y2Ti2O7 and Tb2Ti2O710.1080/08957959.2010.548333 ↗
41. Effect of the substitution of f-electron elements on the structure and elastic properties of UO210.1016/j.jnucmat.2012.09.031 ↗
42. Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides10.1107/S0567739476001551 ↗
43. The plastic deformation of uranium oxides above 800 C10.1016/0022-3115(59)90009-1 ↗
44. Bulk and Young's modulus of doped UO2 by synchrotron diffraction under high pressure and Knoop indentation10.1016/j.jnucmat.2003.10.002 ↗