High-precision molecular dynamics simulation of UO2-PuO2: superionic transition in uranium dioxide
Ural Federal University, 620002, Mira street 19, Yekaterinburg, Russia
arXiv:1102.1553 [cond-mat.mtrl-sci] (8 Feb 2011)
@article{2011arXiv1102.1553P,
author={Potashnikov}, S.~I. and {Boyarchenkov}, A.~S. and {Nekrasov}, K.~A. and {Kupryazhkin}, A.~Y.},
title={“{High-precision molecular dynamics simulation of UO2-PuO2: superionic transition in uranium dioxide}”},
journal={ArXiv e-prints},
archivePrefix={“arXiv”},
eprint={1102.1553},
primaryClass={“cond-mat.mtrl-sci”},
keywords={Condensed Matter – Materials Science, Physics – Chemical Physics},
year={2011},
month={feb},
adsurl={http://adsabs.harvard.edu/abs/2011arXiv1102.1553P},
adsnote={Provided by the SAO/NASA Astrophysics Data System}
}
Our series of articles is devoted to high-precision molecular dynamics simulation of mixed actinide-oxide (MOX) fuel in the rigid ions approximation using high-performance graphics processors (GPU). In this article we assess the 10 most relevant interatomic sets of pair potential (SPP) by reproduction of the Bredig superionic phase transition (anion sublattice premelting) in uranium dioxide. The measurements carried out in a wide temperature range from 300K up to melting point with 1K accuracy allowed reliable detection of this phase transition with each SPP. The {lambda}-peaks obtained are smoother and wider than it was assumed previously. In addition, for the first time a pressure dependence of the {lambda}-peak characteristics was measured, in a range from -5 GPa to 5 GPa its amplitudes had parabolic plot and temperatures had linear (that is similar to the Clausius-Clapeyron equation for melting temperature).
February 9, 2011 by hgpu
