### Abstract

Uranium (U) exhibits a high temperature body-centered cubic (bcc) allotrope that is often stabilized by alloying with transition metals such as Zr, Mo, and Nb for technological applications. One such application involves U-Zr as nuclear fuel, where radiation damage and diffusion (processes heavily dependent on point defects) are of vital importance. Several systems of U are examined within a density functional theory framework utilizing projector augmented wave pseudopotentials. Two separate generalized gradient approximations of the exchange-correlation are used to calculate defect properties and are compared. The bulk modulus, the lattice constant, and the Birch-Murnaghan equation of state for the defect free bcc uranium allotrope are calculated. Defect parameters calculated include energies of formation of vacancies in the α and γ allotropes, as well as self-interstitials, Zr interstitials, and Zr substitutional defects for the γ allotrope. The results for vacancies agree very well with experimental and previous computational studies. The most probable self-interstitial site in γ -U is the (110) dumbbell, and the most probable defect location for dilute Zr in γ -U is the substitutional site. This is the first detailed study of self-defects in the bcc allotrope of U and also the first comprehensive study of dilute Zr defects in γ -U.

Original language | English |
---|---|

Article number | 505703 |

Journal | Journal of Physics Condensed Matter |

Volume | 22 |

Issue number | 50 |

DOIs | |

Publication status | Published - 22 Dec 2010 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Condensed Matter Physics
- Materials Science(all)

### Cite this

*Journal of Physics Condensed Matter*,

*22*(50), [505703]. https://doi.org/10.1088/0953-8984/22/50/505703

**First principles calculations for defects in U.** / Beeler, B.; Good, B.; Rashkeev, Sergey; Deo, C.; Baskes, M.; Okuniewski, M.

Research output: Contribution to journal › Article

*Journal of Physics Condensed Matter*, vol. 22, no. 50, 505703. https://doi.org/10.1088/0953-8984/22/50/505703

}

TY - JOUR

T1 - First principles calculations for defects in U

AU - Beeler, B.

AU - Good, B.

AU - Rashkeev, Sergey

AU - Deo, C.

AU - Baskes, M.

AU - Okuniewski, M.

PY - 2010/12/22

Y1 - 2010/12/22

N2 - Uranium (U) exhibits a high temperature body-centered cubic (bcc) allotrope that is often stabilized by alloying with transition metals such as Zr, Mo, and Nb for technological applications. One such application involves U-Zr as nuclear fuel, where radiation damage and diffusion (processes heavily dependent on point defects) are of vital importance. Several systems of U are examined within a density functional theory framework utilizing projector augmented wave pseudopotentials. Two separate generalized gradient approximations of the exchange-correlation are used to calculate defect properties and are compared. The bulk modulus, the lattice constant, and the Birch-Murnaghan equation of state for the defect free bcc uranium allotrope are calculated. Defect parameters calculated include energies of formation of vacancies in the α and γ allotropes, as well as self-interstitials, Zr interstitials, and Zr substitutional defects for the γ allotrope. The results for vacancies agree very well with experimental and previous computational studies. The most probable self-interstitial site in γ -U is the (110) dumbbell, and the most probable defect location for dilute Zr in γ -U is the substitutional site. This is the first detailed study of self-defects in the bcc allotrope of U and also the first comprehensive study of dilute Zr defects in γ -U.

AB - Uranium (U) exhibits a high temperature body-centered cubic (bcc) allotrope that is often stabilized by alloying with transition metals such as Zr, Mo, and Nb for technological applications. One such application involves U-Zr as nuclear fuel, where radiation damage and diffusion (processes heavily dependent on point defects) are of vital importance. Several systems of U are examined within a density functional theory framework utilizing projector augmented wave pseudopotentials. Two separate generalized gradient approximations of the exchange-correlation are used to calculate defect properties and are compared. The bulk modulus, the lattice constant, and the Birch-Murnaghan equation of state for the defect free bcc uranium allotrope are calculated. Defect parameters calculated include energies of formation of vacancies in the α and γ allotropes, as well as self-interstitials, Zr interstitials, and Zr substitutional defects for the γ allotrope. The results for vacancies agree very well with experimental and previous computational studies. The most probable self-interstitial site in γ -U is the (110) dumbbell, and the most probable defect location for dilute Zr in γ -U is the substitutional site. This is the first detailed study of self-defects in the bcc allotrope of U and also the first comprehensive study of dilute Zr defects in γ -U.

UR - http://www.scopus.com/inward/record.url?scp=78649825146&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=78649825146&partnerID=8YFLogxK

U2 - 10.1088/0953-8984/22/50/505703

DO - 10.1088/0953-8984/22/50/505703

M3 - Article

VL - 22

JO - Journal of Physics Condensed Matter

JF - Journal of Physics Condensed Matter

SN - 0953-8984

IS - 50

M1 - 505703

ER -