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Symmetry reduction of δ-plutonium: an electronic-structure effect

Published online by Cambridge University Press:  26 February 2011

Kevin T. Moore
Affiliation:
[email protected], Lawrence Livermore National Laboratory, Chemistry and Materials Science, 7000 East Ave., Livermore, CA, 94550, United States, 945-422-9741, 925-422-6892
Per Söderlind
Affiliation:
Adam J. Schwartz
Affiliation:
David Laughlin
Affiliation:
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Abstract

Using first-principles density-functional theory calculations, we show that the anomalously large anisotropy of δ-plutonium is a consequence of greatly varying bond-strengths between the 12 nearest neighbors. Employing the calculated bond strengths, we expand the tenants of classical crystallography by incorporating anisotropy of chemical bonds, which yields a structure with the monoclinic space group Cm for δ-plutonium rather than face-centered cubic Fm3m. The reduced space group for δ-plutonium enlightens why the ground state of the metal is monoclinic, why distortions of the metal are viable, and has considerable implications for the behavior of the material as it ages. These results illustrate how an expansion of classical crystallography that accounts for anisotropic electronic structure can explain complicated materials in a novel way.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

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References

REFERENCES

[1] Bloss, F.D.Crystallography and Crystal Chemistry,” (Holt, Rinehart, and Winston Inc. 1971).Google Scholar
[2] Albers, R.C., Nature 410, 759 (2001).Google Scholar
[3] Hecker, S.S., Metall. Mat. Trans. A 35, 2207 (2004).Google Scholar
[4] Skrivers, H.L., Andersen, O.K. and Johansson, B., Phys. Rev. Lett. 41, 42 (1978).Google Scholar
[5] Smith, J.L. and Kmetko, E.A., J Less Comm. Met. 90, 83 (1983).Google Scholar
[6] Savrasov, S.Y., Kotliar, G. and Abrahams, E., Nature 410, 793 (2001).Google Scholar
[7] Moore, K.T. et al. , Phys. Rev. Lett 90, 196404 (2003).Google Scholar
[8] van der Laan, G. et al. , Phys. Rev. Lett 93, 097401 (2004).Google Scholar
[9] Wong, J. et al. , Science 301, 10781080 (2003).Google Scholar
[10] Ledbetter, H.M. and Moment, R.L., Acta Metall. 24, 891 (1976).Google Scholar
[11] McQueeney, R. J. et al. , Phys. Rev. Lett. 92, 146401 (2004).Google Scholar
[12] Stedman, R. and Nilsson, G., Phys. Rev. 145, 492 (1966).Google Scholar
[13] Moore, K.T., Söderlind, P., Schwartz, A.J., Laughlin, D.E., submitted to Phys. Rev. Lett. Google Scholar
[14] Wills, J.M., Eriksson, O., Alouani, M. and Price, D.L., “Electronic Structure and Physical Properties of Solids,” Dreysse, H., editor. (Springer-Verlag, Berlin, 1998).Google Scholar
[15] Ahuja, R., Söderlind, P., Trygg, J., Melsen, J., Wills, J.M., Johansson, B. and Eriksson, O., Phys Rev B 50, 14690 (1994).Google Scholar
[16] Söderlind, P. Adv Phys 47, 959. (1998).Google Scholar
[17] Perdew, J.P, Chevary, J.A., Vosko, S.H., Jackson, K.A., Pederson, M.R. and Singh, D.J., Phys Rev B 46, 6671 (1992).Google Scholar
[18] Perdew, J.P., Burke, K. and Ernzerhof, M., Phys Rev. Lett. 87, 156401 (2001).Google Scholar
[19] Chadi, D.J. and Cohen, M.L., Phys Rev B 8, 5747 (1973).Google Scholar
[20] Laughlin, D.E., Willard, M.A. and McHenry, M.E., “Phase Transformations and Evolution in Materials,” 2000, edited by Turchi, P., Gonis, A. (The Minerals, Metals and Materials Society) pp. 121.Google Scholar
[21] Söderlind, P. et al. , Phys Rev. B 45, 12911 (1992).Google Scholar
[22] Söderlind, P. and Sadigh, B., Phys. Rev. Lett 92, 185702 (2004).Google Scholar
[23] Elliot, R.O. and Gschneidner, K.A. Jr U.S. Patent Office, no. 3,043,727 (1962).Google Scholar
[24] Zukas, E.G. et al. , in Proceedings of an International Conference on Solid→Solid Phase Transformations, edited by Aaronson, H.I. et al. (The Metallurgical Society of AIME, 1981).Google Scholar
[25] King, H.W., J Mater. Sci. 1, 79 (1966).Google Scholar
[26] Predel, B. and Gust, W., Mater. Sci. Eng. 10, 211 (1972).Google Scholar
[27] Lawson, A.C. et al. , Phil Mag. B 80, 1869 (2000).Google Scholar
[28] Lawson, A.C. et al. , Phil Mag. B 85, 2007 (2005).Google Scholar
[29] Zocco, T.G. et al. , Acta Metall. 38, 2275 (1990).Google Scholar
[30] Schwartz, A.J. et al. ., Phil. Mag. 85, 479 (2005).Google Scholar
[31] Dai, X. et al. , Science 300, 953 (2003).Google Scholar
[32] Robert, G., Pasturel, A., and Siberchicot, B., J Phys. Con. Mat. 15, 8377 (2003).Google Scholar
[33] Cox, L.E. et al. , Phys Rev. B 51, 751 (1995).Google Scholar
[34] Coppens, P., X-ray charge densities and chemical bonding (Oxford University Press, 1997).Google Scholar
[35] We have attempted detection of extra reflections using electron diffraction in a transmission electron microscope (TEM). However, high thermal diffuse scattering, large amounts of double diffraction due to the high atomic number, and omnipresent surface oxidation have precluded the ability to do this. For these reasons, x-ray diffraction of large, single-grain samples performed at low temperatures will be the appropriate experiment.Google Scholar