TY - JOUR
T1 - Crystal structure of U1-yLnyO2-x (Ln = Gd, Er) solid solution
AU - Van Mao, Pham
AU - Arima, Tatsumi
AU - Inagaki, Yaohiro
AU - Idemitsu, Kazuya
AU - Akiyama, Daisuke
AU - Nagai, Takayuki
AU - Okamoto, Yoshihiro
N1 - Funding Information:
The authors would like to thank Prof. Akira Kirishima, Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, for allowing us to do many experiments during sample preparation and characterization at IMRAM. This work was partially supported by MEXT Innovative Nuclear Research and Development Program Grant No. JPMXD0219214921 and the Cooperative Research Program “Network Joint Research Center for Materials and Devices”.
Funding Information:
The authors would like to thank Prof. Akira Kirishima, Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, for allowing us to do many experiments during sample preparation and characterization at IMRAM. This work was partially supported by MEXT Innovative Nuclear Research and Development Program Grant No. JPMXD0219214921 and the Cooperative Research Program ?Network Joint Research Center for Materials and Devices?.
Publisher Copyright:
© 2021
PY - 2021/12/1
Y1 - 2021/12/1
N2 - The crystal structure was evaluated for U1-yLnyO2-x (Ln = Gd, Er; y = 0−0.4) samples sintered at 1973 K for 8 h under Ar and Ar-10% H2 atmospheres. The effect of LnO1.5 doping on the crystal structure was investigated by X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS). The structures were refined by Rietveld analysis of the XRD patterns. LnO1.5 doping into UO2 reduced the lattice parameter of UO2−LnO1.5 solid solutions up to 40 mol % LnO1.5. The lattice parameters of these samples were comparable to those of stoichiometric (U,Ln)O2.00 solid solutions, that is, the O/M ratios were close to 2.00. XAFS spectra in the X-ray absorption near edge structure region showed that higher U oxidation states of +5 or +6 formed, in addition to +4. Extended XAFS indicated that the interatomic distances of U−O and Gd−O decreased with increasing y, whereas those of Er−O may not decrease monotonically.
AB - The crystal structure was evaluated for U1-yLnyO2-x (Ln = Gd, Er; y = 0−0.4) samples sintered at 1973 K for 8 h under Ar and Ar-10% H2 atmospheres. The effect of LnO1.5 doping on the crystal structure was investigated by X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS). The structures were refined by Rietveld analysis of the XRD patterns. LnO1.5 doping into UO2 reduced the lattice parameter of UO2−LnO1.5 solid solutions up to 40 mol % LnO1.5. The lattice parameters of these samples were comparable to those of stoichiometric (U,Ln)O2.00 solid solutions, that is, the O/M ratios were close to 2.00. XAFS spectra in the X-ray absorption near edge structure region showed that higher U oxidation states of +5 or +6 formed, in addition to +4. Extended XAFS indicated that the interatomic distances of U−O and Gd−O decreased with increasing y, whereas those of Er−O may not decrease monotonically.
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U2 - 10.1016/j.jnucmat.2021.153189
DO - 10.1016/j.jnucmat.2021.153189
M3 - Article
AN - SCOPUS:85110685674
VL - 556
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
SN - 0022-3115
M1 - 153189
ER -