TY - JOUR
T1 - Lattice expansion by intrinsic defects in uranium by molecular dynamics simulation
AU - Li, Yangzhong
AU - Chernatynskiy, Aleksandr
AU - Kennedy, J. Rory
AU - Sinnott, Susan B.
AU - Phillpot, Simon R.
N1 - Funding Information:
This work was authored by subcontractors (YL, AC, SRP) of the U.S. Government under DOE Contract No. DE-AC07-05ID14517, under the Energy Frontier Research Center (Office of Science, Office of Basic Energy Science, FWP 1356) and by JRK under DOE Idaho Operations Office Contract DE-AC07-051D14517 as part of the Nuclear Science User Facilities (Office of Nuclear Energy). Accordingly, the U.S. Government retains and the publisher (by accepting the article for publication) acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. Government purposes.
Publisher Copyright:
© 2016 Elsevier B.V. All rights reserved.
PY - 2016/7
Y1 - 2016/7
N2 - A re-formulated and re-parameterized interatomic potential for uranium metal in the Charge-Optimized Many-Body (COMB) formalism is presented. Most physical properties of the orthorhombic α and bcc γ phases are accurately reproduced. In particular, this potential can reproduce the negative thermal expansion of the b axis in α-U while keeping this phase as the most stable phase at low temperatures, in accord with experiment. Most of the volume expansion in α-U by intrinsic defects is shown to come from the b axis, due to the formation of prismatic loops normal to this direction. Glide dislocation loops forming stacking faults are also observed. Structures of both loop types are analyzed. An expansion simulation is conducted and the results are verified by using the Norgett-Robinson-Torrens model. Rather than forming extended defect structures as in α-U, the γ phase forms only isolated defects and thus results in a much smaller and isotropic expansion.
AB - A re-formulated and re-parameterized interatomic potential for uranium metal in the Charge-Optimized Many-Body (COMB) formalism is presented. Most physical properties of the orthorhombic α and bcc γ phases are accurately reproduced. In particular, this potential can reproduce the negative thermal expansion of the b axis in α-U while keeping this phase as the most stable phase at low temperatures, in accord with experiment. Most of the volume expansion in α-U by intrinsic defects is shown to come from the b axis, due to the formation of prismatic loops normal to this direction. Glide dislocation loops forming stacking faults are also observed. Structures of both loop types are analyzed. An expansion simulation is conducted and the results are verified by using the Norgett-Robinson-Torrens model. Rather than forming extended defect structures as in α-U, the γ phase forms only isolated defects and thus results in a much smaller and isotropic expansion.
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U2 - 10.1016/j.jnucmat.2016.03.018
DO - 10.1016/j.jnucmat.2016.03.018
M3 - Article
AN - SCOPUS:84962674759
SN - 0022-3115
VL - 475
SP - 6
EP - 18
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
ER -