Oxygen self-diffusion in ThO₂ under pressure: Connecting point defect parameters with bulk properties

Journal Article · 06 June 2016 · Materials Research Express (Online)

DOI: https://doi.org/10.1088/2053-1591/3/6/065501 · OSTI ID:1296676

Cooper, Michael William D. ^[1]; Fitzpatrick, M. E. ^[2]; Tsoukalas, L. H. ^[3]; Chroneos, A. ^[2]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Coventry Univ., Coventry (United Kingdom)
3. Purdue Univ., West Lafayette, IN (United States)

ThO₂ is a candidate material for use in nuclear fuel applications and as such it is important to investigate its materials properties over a range of temperatures and pressures. In the present study molecular dynamics calculations are used to calculate elastic and expansivity data. These are used in the framework of a thermodynamic model, the cBΩ model, to calculate the oxygen self-diffusion coefficient in ThO₂ over a range of pressures (–10–10 GPa) and temperatures (300–1900 K). As a result, increasing the hydrostatic pressure leads to a significant reduction in oxygen self-diffusion. Conversely, negative hydrostatic pressure significantly enhances oxygen self-diffusion.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1296676
• Report Number(s): LA-UR-15-28611
• Journal Information: Materials Research Express (Online), Vol. 3, Issue 6; ISSN 2053-1591
• Publisher: IOP PublishingCopyright Statement
• Country of Publication: United States
• Language: English