TY - JOUR
T1 - Structure and bulk modulus of Ln-doped UO2 (Ln = La, Nd) at high pressure
AU - Rittman, Dylan R.
AU - Park, Sulgiye
AU - Tracy, Cameron L.
AU - Zhang, Lei
AU - Palomares, Raul I.
AU - Lang, Maik
AU - Navrotsky, Alexandra
AU - Mao, Wendy L.
AU - Ewing, Rodney C.
N1 - Funding Information:
This work was supported as part of “Materials Science of Actinides”, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE) Office of Science, Basic Energy Sciences (Grant No. DE-SC0001089). X-ray diffraction data were collected at beamlines HPCAT (Sector 16), APS, ANL and 12.2.2, ALS, LBNL. HPCAT operations are supported by DOE-NNSA under Award No. DE-NA0001974 and DOE-BES under Award No. DE-FG02-99ER45775, with partial instrumentation funding by NSF. The APS is a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by ANL under Contract No. DE-AC02-06CH11357. The ALS is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. DOE under Contract No. DE-AC02-05CH11231. Beamline 12.2.2 is partially supported by COMPRES, the Consortium for Materials Properties Research in Earth Sciences under NSF Cooperative Agreement EAR 1606856. R.I.P. gratefully acknowledges the support of the Carnegie-DOE Alliance Center under cooperative agreement DE-NA0002006. Travel for D.R.R. and S.P. was partially supported by the McGee Research Grant program through Stanford University.
Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/7/1
Y1 - 2017/7/1
N2 - 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.
AB - 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.
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U2 - 10.1016/j.jnucmat.2017.04.007
DO - 10.1016/j.jnucmat.2017.04.007
M3 - Article
AN - SCOPUS:85017421890
SN - 0022-3115
VL - 490
SP - 28
EP - 33
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
ER -