Abstract
In this work we used ab initio molecular dynamics within the framework of density functional theory and the projector-augmented wave method to study carbon diffusion in liquid uranium at temperatures above 1600 K. The electronic interactions of carbon and uranium were described using the local density approximation (LDA). The self-diffusion of uranium based on this approach is compared with literature computational and experimental results for liquid uranium. The temperature dependence of carbon and uranium diffusion in the melt was evaluated by fitting the resulting diffusion coefficients to an Arrhenius relationship. We found that the LDA calculated activation energy for carbon was nearly twice that of uranium: 0.55 0.03 eV for carbon compared to 0.32 0.04 eV for uranium. Structural analysis of the liquid uranium-carbon system is also discussed.
Original language | English |
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Article number | 035013 |
Journal | Modelling and Simulation in Materials Science and Engineering |
Volume | 26 |
Issue number | 3 |
DOIs | |
State | Published - Mar 6 2018 |
Externally published | Yes |
Funding
We thank Andrew Ritzmann, Lewis Johnson, Micah Prange, and Peter Sushko for useful discussion and suggestions regarding this work. This work was supported by the Nuclear Process Science Initiative (NPSI) at the Pacific Northwest National Laboratory (PNNL). Computational resources were provided by PNNL Institutional Computing (PIC). This work was performed at Pacific Northwest National Laboratory which is operated by the Battelle Memorial Institute for the US Department of Energy under Contract No. DE-AC06-76RLO-1830.
Keywords
- ab initio molecular dynamics
- actinide chemistry
- condensed phase
- diffusion
- dynamical properties
- high temperature simulation
- materials science