Mechanical and electronic properties of CeO{sub 2}, ThO{sub 2}, and (Ce,Th)O{sub 2} alloys

Journal Article · Wed Jul 01 04:00:00 EDT 2009 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.80.014108· OSTI ID:21287036

Sevik, C; Cagin, T ^[1]

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1. Department of Chemical Engineering and Material Science and Engineering, Texas A and M University, College Station, Texas 77845-3122 (United States)

A systematic first-principle study is conducted to calculate bulk modulus, elastic constants, phonon-dispersion curves, and electronic structures of CeO{sub 2}, ThO{sub 2}, and their ordered binary alloys Ce{sub x}Th{sub 8-x}O{sub 16} with x=1, 2, 4, 6, and 7 using local-density approximation (LDA), generalized gradient approximation (GGA), LDA+U, and GGA+U approaches. In order to get accurate results for these type of systems including f electrons [Ce(4f) and Th(5f)] we optimized the U parameter for use in LDA+U and GGA+U approaches. The computed structural, mechanical, and electronic properties of CeO{sub 2} and ThO{sub 2} are observed to display strong correlation with experimental data. In particular, the best agreement with experiment is obtained within the LDA+U in which on-site Coulomb interaction parameter (U{sub eff}) for Ce and Th are taken as 6.0 and 5.0 eV. To check the stability of alloy forms, phonon-dispersion curves of Ce{sub x}Th{sub 8-x}O{sub 16} with x=2, 4, and 6 are computed. In all concentrations, mechanical stability conditions are satisfied for alloys. Furthermore, we observed no negative phonon branches in the phonon spectrum of alloys. Our calculations indicated a strong effect of concentration, x, on the electronic structure of Ce{sub x}Th{sub 8-x}O{sub 16}.

• OSTI ID: 21287036
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 1 Vol. 80; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
APPROXIMATIONS
BINARY ALLOY SYSTEMS
CERIUM ALLOYS
CERIUM OXIDES
CORRELATIONS
DENSITY FUNCTIONAL METHOD
DISPERSION RELATIONS
DISPERSIONS
ELECTRICAL PROPERTIES
ELECTRONIC STRUCTURE
ELECTRONS
INTERACTIONS
MECHANICAL PROPERTIES
OXIDES
PHONONS
SIMULATION
SPECTRA
STABILITY
THORIUM ALLOYS
THORIUM OXIDES