Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-13T02:23:10.214Z Has data issue: false hasContentIssue false
  • English
  • Français

Local Structure of Simplified Waste Glass: Complementarity of XAS and MD Calculations

Published online by Cambridge University Press:  10 February 2011

L Galoisy ,
J.M. Delaye ,
D. Ghaleb ,
G. Calas ,
M. Le Grand ,
G. Morin ,
A. Ramos  and
F. Pacaud
L Galoisy
Affiliation:
Laboratoire de Minéralogie-Cristallographie, URA CNRS 09, Universités Paris6 et 7 and IPGP, 75252 Paris, France
J.M. Delaye
Affiliation:
DTA/DECM/SRMP C.E.A. Saclay, 91191 Gif/Yvette Cedex, France
D. Ghaleb
Affiliation:
DCC/DRDD/SCD C.E.A. Valrho-Marcoule, Bp 171 – 30207 Bagnols/céze Cedex, France
G. Calas
Affiliation:
Laboratoire de Minéralogie-Cristallographie, URA CNRS 09, Universités Paris6 et 7 and IPGP, 75252 Paris, France
M. Le Grand
Affiliation:
DCC/DRDD/SCD C.E.A. Valrho-Marcoule, Bp 171 – 30207 Bagnols/céze Cedex, France Laboratoire de Minéralogie-Cristallographie, URA CNRS 09, Universités Paris6 et 7 and IPGP, 75252 Paris, France
G. Morin
Affiliation:
Laboratoire de Minéralogie-Cristallographie, URA CNRS 09, Universités Paris6 et 7 and IPGP, 75252 Paris, France
A. Ramos
Affiliation:
Laboratoire de Minéralogie-Cristallographie, URA CNRS 09, Universités Paris6 et 7 and IPGP, 75252 Paris, France
F. Pacaud
Affiliation:
DCC/DRDD/SCD C.E.A. Valrho-Marcoule, Bp 171 – 30207 Bagnols/céze Cedex, France
Get access

Abstract

X-ray Absorption Spectroscopy (XAS) together with x-ray diffraction methods were used in inactive analogues of the French nuclear waste glass to analyze Pd-Te precipitates and the peculiarity of the sites occupied by some structural probe elements such as Mo, Zn, Zr and Si in the glassy part of the material. The influence of the precipitates on the structure of the glassy matrix around these structural probes was investigated by comparing noble metal bearing compositions together with noble metal free glasses.

In noble metal bearing glasses, Pd is associated to Te as (Pd90 Te10) precipitates. Pd K-edge EXAFS shows the presence of Te in the Pd coordination shell and is in accordance with a non-metallic character of the Pd-Te bond. Mo K-edge EXAFS shows that Mo occurs as molybdate groups non connected to the glassy matrix, which may be related to the occasional separation of Mo-rich phases in some compositions. Zr is located in an octahedron with d(Zr-O)=2.08Å 0.01Å whereas Zn is 4-fold coordinated with d(Zn-0)=-1.95 ű 0.01Å. Beyond this well defined first coordination shell, XAS detects some degree of medium range order which gives insight on the bonding of the site to the polymeric borosilicate network. The interatomic Zn-Si and Zr-Si EXAFS-determined distances agree with a ZnO4 and Si04 tetrahedra sharing corners geometry and Zr-Si octahedra sharing corner with Si04 tetrahedra. A third shell of neighbors around Zr was evidenced in the noble metal bearing glasses and in a four oxide glass, indicating that Zr is an element useful for detecting subtle changes in the local structure of complex borosilicate glasses. Si K XANES shows modifications in the connection between Si04 tetrahedra when noble metals are present. To obtain accurate and precise structural interpretations, a direct comparison between EXAFS data and Molecular Dynamic (M.D.) calculations on simplified nuclear glass comprising six oxides has been performed. MD calculations show that the distribution of the Zr-O distances is harmonic in the k-range accessible with EXAFS in glasses.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 506: Symposium – Scientific Basis for Nuclear Waste Management XXI , 1997 , 133
Copyright
Copyright © Materials Research Society 1998

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

1 Puyou, M., Jacquet-Francillon, N., Moncouyoux, J.P., Sombret, C. and Teulon, F., Nucl. Technol. 111, 163–168 (1995)Google Scholar
2 Krause, Ch. and Luckscheiter, B., J. Mater. Res. 6, 2535–2546 (1991)Google Scholar
3 Brown, G.E. Jr, Farges, F. and Calas, G. in Structure, Dynamics and Properties of silicate melts Reviews in Mineralogy Ed Ribbe, P.H., Mineralogical Society of America (1995)Google Scholar
4 Delaye, J.M. and Ghaleb, D., J. Non-Cryst. Sol., 195, 239 (1996)Google Scholar
5 Jacquet-Francillon, N., Bonniaud, R. and Sombret, C., Radiochim. Acta, 25, 231 (1981)Google Scholar
6 Krause, Ch. and Luckscheiter, B., J. Mater. Res. 6, 2535–2546 (1991)Google Scholar
7 Ladiat, C., Boin, R., Jouan, A. and Moncouyoux, J.P. “55th conference on glass problems”, 3, 11–14. Drummond, Ch. H. ed. (1989)Google Scholar
8 Galoisy, L. and Calas, G., Amer. Min., 76, 1777–1780 (1991)Google Scholar
9 Galoisy, L. and Calas, G. Geochim. Cosmochim. Acta, 57, 3613–3626 (1993)Google Scholar
10 McKale, A.G., Veal, B.W., Paulikas, A.P., Chan, S.K. and Knapp, G.S., J. Am. Chem. Soc., 110, 3763–3768 (1988)Google Scholar
11 Teo, B.K. Inorg. Chem. Concepts, 9 (1986)Google Scholar
12 Delaye, J.M. and Ghaleb, D., Mat. Sc.& Ing. B37, 232 (1996)Google Scholar
13 Delaye, J.M and Ghaleb, D.. J. Nucl. Mat., 244, 22 (1997)Google Scholar
14 Delaye, J.M, Louis-Achille, V. and Ghaleb, D., J. Non-Cryst. Sol., 210, 232 (1997)Google Scholar
15 Pacaud, F., Fillet, C. and Jacquet-Francillon, N., Mat. Res. Soc. Symp. Proc. 257, 161–167 (1992)Google Scholar
16 Kelm, M. and Oser, B., Mat. Res. Soc. Symp. Proc. 257, 177–182 (1992)Google Scholar
17 Matkovic, P. and Schubert, K., J. Less Common Metals, 58, P39–P46 (1978)Google Scholar
18 Petit-Maire, D., These de Doctorat Université Paris VI (1988).Google Scholar
19 Farges, F., Ponader, C.W. and Brown, G. E. Jr, Geochim. Cosmochim. Acta 55, 1563–74 (1991).Google Scholar
20 Davoli, I., Paris, E., Stizza, S., Benfatto, M., Fanfoni, M., Gargano, A., Bianconi, A. and Seifert, F. Phys. Chem. Minerals, 19, 171–175 (1992)Google Scholar
21 Wu, Z. and Seifert, F. Solid State comm. 99, 773–778 (1996)Google Scholar
22 Henderson, G.S., J. Non Cryst. Solids 183, 43–50 (1995).Google Scholar