skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Structure and cation ordering in La2UO6, Ce2UO6, LaUO4, and CeUO4 by first principles calculations

Journal Article · · Computational Materials Science
 [1];  [1];  [2];  [2];  [3];  [1]
  1. Univ. of Tennessee, Knoxville, TN (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. CNRS, Chatenay-Malabry (France)
+ Show Author Affiliations

In the present work, we have used density functional theory (DFT) and DFT+U to investigate the crystal structure and phase stability of four model compounds in the Ln2O3-UO2-UO3 ternary oxide system: La2UO6, Ce2UO6, LaUO4, CeUO4, due to the highly-correlated nature of the f-electrons in uranium. We have considered both hypothetical ordered compounds and compounds in which the cations randomly occupy atomic sites in a fluorite-like lattice. We determined that ordered compounds are stable and are energetically favored compared to disordered configurations, though the ordering tendencies are weak. To model and analyze the structures of these complex oxides, we have used supercells based on a layered atomic model. In the layer model, the supercell is composed of alternating planes of anions and cations. We have considered two different ordering motifs for the cations, namely single species (isoatomic) cation layers versus mixed species cation layers. Energy differences between various ordered cationic arrangements were found to be small. This may have implications regarding radiation stability, since cationic arrangements should be able to change under irradiation with little cost in energy.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Nuclear Energy (NE); USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
AC05-00OR22725; NA0001983; UT-TENN0112
OSTI ID:
1360025
Alternate ID(s):
OSTI ID: 1397519
Journal Information:
Computational Materials Science, Vol. 123; ISSN 0927-0256
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 4 works
Citation information provided by
Web of Science

Similar Records

One-dimensional chains in uranyl tungstates: Syntheses and structures of A{sub 8}[(UO{sub 2}){sub 4}(WO{sub 4}){sub 4}(WO{sub 5}){sub 2}] (A=Rb, Cs) and Rb{sub 6}[(UO{sub 2}){sub 2}O(WO{sub 4}){sub 4}]
Journal Article · Sun Oct 15 00:00:00 EDT 2006 · Journal of Solid State Chemistry · OSTI ID:1360025
+4 more
f-Element/crown ether complexes. 10. Oxidation of UCl/sub 4/ to (UO/sub 2/Cl/sub 4/)/sup 2/minus// in the presence of crown ethers: Structural characterization of crown ether complexed ammonium ions ((NH/sub 4/)(15-crown-5)/sub 2/)/sub 2/(UO/sub 2/Cl/sub 4/) /times/2CH/sub 3/CN, ((NH/sub 4/)(benzo-15-crown-5)/sub 2/)/sub 2/(UCl/sub 6/) /times/ 4CH/sub 3/CN, and ((NH/sub 4/)(dibenzo-18-crown-6))/sub 2/(UO/sub 2/Cl/sub 4/) /times/ 2CH/sub 3/CN and synthesis of (Na(12-crown-4)/sub 2/)/sub 2/(UO/sub 2/Cl/sub 4/) /times/ 2OHMe and (UO/sub 2/Cl/sub 2/(OH/sub 2/)/sub 3/) /times/ 18-crown-6 /times/ H/sub 2/O /times/ OHMe
Journal Article · Wed Dec 30 00:00:00 EST 1987 · Inorg. Chem.; (United States) · OSTI ID:1360025
Crystal chemistry of anhydrous Li uranyl phosphates and arsenates. II. Tubular fragments and cation-cation interactions in the 3D framework structures of Li{sub 6}[(UO{sub 2}){sub 12}(PO{sub 4}){sub 8}(P{sub 4}O{sub 13})], Li{sub 5}[(UO{sub 2}){sub 13}(AsO{sub 4}){sub 9}(As{sub 2}O{sub 7})], Li[(UO{sub 2}){sub 4}(AsO{sub 4}){sub 3}] and Li{sub 3}[(UO{sub 2}){sub 7}(AsO{sub 4}){sub 5}O]
Journal Article · Sun Nov 15 00:00:00 EST 2009 · Journal of Solid State Chemistry · OSTI ID:1360025

Related Subjects

36 MATERIALS SCIENCE