Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-24T09:45:54.312Z Has data issue: false hasContentIssue false

Thermal Jamming of Ions in the Superionic State of UO2

Published online by Cambridge University Press:  02 April 2018

Dillon Sanders*
Affiliation:
Department of Nuclear Engineering, North Carolina State University, Raleigh, NC27695, U.S.A.
Jacob Eapen
Affiliation:
Department of Nuclear Engineering, North Carolina State University, Raleigh, NC27695, U.S.A.
*
Get access

Abstract

The oxygen ions in the high temperature superionic state of uranium dioxide (UO2) are known to be in an arrested or jammed state, exhibiting characteristic features of jammed kinetics such as low dimensional string-like ion hopping and dynamical heterogeneity (DH). This thermally-jammed state entails a configurational entropic cost. Using atomistic simulations and the 2PT method, we compute the solid-like (vibrational) and hard sphere-like (configurational) contributions to the total entropy across a temperature range of 1500 K to 2800 K that envelop both the onset of superionic conduction (2000 K) and the second order λ-transition (2610 K). To properly account for the thermally jammed state of the ions, we use an equation of state that is appropriate for the metastable fluid branch. Our simulation results are in excellent agreement with the entropy data extracted from specific heat experiments with a mean error of less than 2%.

Type
Articles
Copyright
Copyright © Materials Research Society 2018 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Hull, S., Rep. Prog. Phys., 67 (2004) 1233.Google Scholar
Annamareddy, A., Eapen, J., J. Nucl. Mater., 483 (2017) 132141.Google Scholar
Annamareddy, A., Eapen, J., J. Chem. Phys., 143 (2015) 194502.Google Scholar
Clausen, K., Hayes, W., Macdonald, J.E., Osborn, R., Hutchings, M.T., Phy. Rev. Lett., 52 (1984) 12381241.CrossRefGoogle Scholar
Ralph, J., Hyland, G.J., J. Nucl. Mater., 132 (1985) 7679.Google Scholar
Annamareddy, A., Eapen, J., Sci. Reports, 7 (2017) 44149.Google Scholar
Annamareddy, V.A., Nandi, P.K., Mei, X., Eapen, J., Phys. Rev. E, 89 (2014) 010301.Google Scholar
Gray-Weale, A., Madden, P.A., J. Phys. Chem. B, 108 (2004) 66246633.Google Scholar
Zhang, H., Khalkhali, M., Liu, Q., Douglas, J.F., J. Chem. Phys., 138 (2013) 12A538516.Google Scholar
Chaudhuri, P., Berthier, L., Kob, W., Phys. Rev. Lett., 99 (2007) 060604.CrossRefGoogle Scholar
Lin, S.-T., Blanco, M., Goddard, W.A., J. Chem. Phys., 119 (2003) 11792.Google Scholar
Wang, J., Chakraborty, B., Eapen, J., Phys. Chem. Chem. Phys., 16 (2014) 30623069.CrossRefGoogle ScholarPubMed
Huang, S.-N., Pascal, T.A., Goddard, W.A., Maiti, P.K., Lin, S.-T., J. Chem. Theory Comput., 7 (2011) 18931901.Google Scholar
Petridis, L., Schulz, R., Smith, J.C., J. Amer. Chem. Soc., 133 (2011) 20277.Google Scholar
Yakub, E., Ronchi, C., Staicu, D., J. Chem. Phys., 127 (2007) 094508094511.Google Scholar
Wu, G.-W., Sadus, R.J., AIChE Journal, 51 (2005) 309313.Google Scholar
Speedy, R.J., Mol. Phys., 95 (1998) 169.Google Scholar