Simulation of thermodynamic mixing properties of actinide-containing zircon solid solutions

American Mineralogist

Volumn 95, Issue 2-3, 2010, Pages 229-241

  Ferriss, E D A ^a   Ewing, R C ^a   Becker, U ^a  

^a UNIVERSITY OF MICHIGAN   (United States)

Author keywords

Coffinite; Hafnon; Monte Carlo simula tion; Quantum mechanics; Solid solution; Thorite; Zircon

Indexed keywords

CERIUM OXIDE; DENSITY FUNCTIONAL THEORY; GEOCHRONOLOGY; HAFNIUM COMPOUNDS; MIXING; MONTE CARLO METHODS; NANOCRYSTALLINE MATERIALS; PHOSPHATE MINERALS; PLUTONIUM COMPOUNDS; QUANTUM THEORY; QUARTZ; RADIOACTIVE MATERIALS; SILICATE MINERALS; SILICON; SOLUBILITY; TEXTURES; THERMODYNAMICS; THORIA; URANIUM DIOXIDE; ZIRCON;

BINARY SOLID SOLUTIONS; COFFINITE; ELECTRONIC MATERIALS; HAFNON; MONOCLINIC POLYMORPHS; THERMODYNAMIC EQUILIBRIA; THERMODYNAMIC INTEGRATION; THORITE;

SOLID SOLUTIONS;

ACTINIDE; ESTIMATION METHOD; EXSOLUTION; LOW TEMPERATURE; MONTE CARLO ANALYSIS; ORTHOSILICATE; QUANTUM MECHANICS; SOLID SOLUTION; THERMODYNAMICS; ZIRCON;

EID: 77950248302     PISSN: 0003004X     EISSN: None     Source Type: Journal    
DOI: 10.2138/am.2010.3318     Document Type: Article

References (129)

1. 2 nuclear fuel. Journal of Nuclear Materials, 341, 209-223.
2. Anderson, E.B., Burakov, B.E., and Pazukhin, E.M. (1993) High-uranium zircon from Chernobyl lavas. Radiochimica Acta, 60, 149-151.
3. Babsail, L., Hamelin, N., and Townsend, P.D. (1991) Helium-ion implanted waveguides in zircon. Nuclear Instruments and Methods in Physics Research, 859, 1219-1225.
4. Baker, F.B., Huber Jr., E.J., Holley Jr., C.E., and Krikoria, Nh. (1971) Enthalpies of formation of cerium dioxide, cerium sesquicarbide, and cerium dicarbide. Journal of Chemical Thermodynamics, 3, 77-83.
5. 4+ impurity centres. Physica Status Solidi (a): Applied Research, 36, 307-316.
6. Ballard, J.R., Palin, J.M., and Campbell, I.H. (2002) Relative oxidation states of magmas inferred from Ce(IV)/Ce(III) in zircon: Application to porphyry copper deposits of northern Chile. Contributions to Mineralogy and Petrology, 144, 347-364.
7. Ballman, A.A. and Laudise, R.A. (1965) Crystallization and solubility of zircon and phenacite in certain molten salts. Journal of the American Ceramic Society, 48, 130-133.
8. Becker, U. and Pollok, K. (2002) Molecular simulations of interfacial and thermodynamic mixing properties of grossular-andradite garnets. Physics and Chemistry of Minerals, 29, 52-64.
9. Becker, U., Fernandez-Gonzalez, A., Prieto, M., Harrison, R., and Putnis, A. (2000) Direct calculation of thermodynamic properties of the barite/celestite solid solution from molecular principles. Physics and Chemistry of Minerals, 27, 291-300.
10. 4). Journal of Nuclear Materials, 278, 212-224.
11. Bosenick, A., Dove, M.T., Myers, E.R., Palin, E.J., Sainz-Diaz, C.I., Guiton, B.S., Warren, M.C., Craig, M.S., and Redfern, S.A.T. (2001) Computational methods for the study of energies of cation distributions: applications to cation-ordering phase transitions and solid solutions. Mineralogical Magazine, 65, 193-219.
12. Breiter, K., Förster, H.J., and Skoda, R. (2006) Extreme P-, Bi-, Nb-, Sc-, U-, and F-rich zircon from fractionated perphosphorous granites: The peraluminous Podlesi granite system, Czech Republic. Lithos, 88, 15-34.
13. Bros, R., Hidaka, H., Kamei, G., and Ohnuki, T. (2003) Mobilization and mechanisms of retardation in the Oklo natural reactor zone 2 (Gabon): Inferences from U, REE, Zr, Mo, and Se isotopes. Applied Geochemistry, 18, 1807-1824.
14. Burakov, B.E., Anderson, E.B., Rovsha, V.S., Ushakov, S.V., Ewing, R.C., Lutze, W., and Weber, W.J. (1996) Synthesis of zircon for immobilization of actinides. Scientific Basis for Nuclear Waste Management XIX, 412, 33-39.
15. 4. Scientific Basis for Nuclear Waste Management XXIV, 663, 307-313.
16. 4. Radiochimica Acta, 90, 95-97.
17. Burton, B.P., van de Walle, A., and Kattner, U. (2006) First principles phase diagram calculations for the wurtzite-structure systems AlN-GaN, GaN-InN, and AlN-InN. Journal of Applied Physics, 100, 113528.
18. Cao, X.Q., Vassen, R., and Stoever, D. (2004) Ceramic materials for thermal barrier coatings. Journal of the European Ceramic Society, 24, 1-10.
19. Caruba, R. and Iacconi, P. (1983) Pegmatitic zircons from Narssarssuk, Greenland; water and OH groups in metamict zircons. Chemical Geology, 38, 75-92.
20. Caruba, R., Baumer, A., and Turco, G. (1975) Nouvelles synthéses hydrothermales du zircon: substitutions isomorphiques; relation morphologie-milieu de croissance. Geochimica et Cosmochimica Acta, 39, 11-26.
21. Cherniak, D.J., Hanchar, J.M., and Watson, E.B. (1997a) Diffusion of tetravalent cations in zircon. Contributions to Mineralogy and Petrology, 127, 383-390.
22. - (1997b) Rare-earth diffusion in zircon. Chemical Geology, 134, 289-301.
23. Cohen, R.E. (2000) Theory of ferroelectrics: a vision for the next decade and beyond. Journal of Physics and Chemistry of Solids, 61, 139-146.
24. Davies, P.K. and Navrotsky, A. (1983) Quantitative correlations of deviations from ideality in binary and pseudobinary solid-solutions. Journal of Solid State Chemistry, 46, 1-22.
25. 2O; < n < 2, associated with organic matter: a case study from Grants uranium region, New Mexico, U.S.A. Chemical Geology, 251, 33-49.
26. Vettraino, F., Magnani, G., La Torretta, T., Marmo, E., Coelli, S., Luzzi, L., Ossi, P., and Zappa, G. (1999) Preliminary fabrication and characterization of inert matrix and thoria fuels for plutonium disposition in light water reactors. Journal of Nuclear Materials, 274, 23-33.
27. - (2001) Computer simulations of solid solutions. In C.A. Geiger, Ed., Solid Solutions in Silicate and Oxide Systems, 3, p. 225-250. European Notes in Mineralogy, Eötvös University Press, Budapest.
28. Essene, E. (1989) The current status of thermobarometry in metamorphic rocks. Geological Society Special Publication, 43, 1-44.
29. Ewing, R.C., Lutze, W., and Weber, W.J. (1995) Zircon: A host-phase for the disposal of weapons plutonium. Journal of Materials Research, 10, 243-246.
30. 4. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1, 538-541.
31. Farnan, I., Cho, H., and Weber, W.J. (2007) Quantification of actinide alpha-radiation damage in minerals and ceramics. Nature, 445, 190-193.
32. Ferriss, E.D.A., Essene, E., and Becker, U. (2008) Computational study of the effect of pressure on the Ti-in-zircon geothermometer. European Journal of Mineralogy, 20, 745-755.
33. Finch, R.J. and Hanchar, J.M. (2003) Structure and chemistry of zircon and zircon-group minerals. In J.M. Hanchar, and P.W.O. Hoskin, Eds., Zircon, 53, p. 1-21. Reviews in Mineralogy and Geochemistry, Mineralogical Society of America, Chantilly, Virginia.
34. 2 at 298.15 K. Journal of Chemical Physics, 65, 1124-1129.
35. Förster, H.J. (2006) Composition and origin of intermediate solid solutions in the system thorite-xenotime-zircon-coffinite. Lithos, 88, 35-55.
36. Fuchs, L.H. and Gebert, E. (1958) X-ray studies of synthetic coffinite, thorite and uranothorites. American Mineralogist, 43, 243-248.
37. Fuchs, L.H. and Hoekstra, H.R. (1959) The preparation and properties of uranium(IV) silicate. American Mineralogist, 44, 1057-1063.
38. Geisler, T., Burakov, B.E., Zirlin, V., Nikolaeva, L., and Poml, P. (2005) A Raman spectroscopic study of high-uranium zircon from the Chernobyl "lava." European Journal of Mineralogy, 17, 883-894.
39. Geisler, T., Schaltegger, U., and Tomaschek, F. (2007) Re-equilibration of zircon in aqueous fluids and melts. Elements, 3, 43-50.
40. Gibb, F.G.F., Taylor, K.J., and Burakov, B.E. (2008) The 'granite encapsulation' route to the safe disposal of Pu and other actinides. Journal of Nuclear Materials, 374, 364-369.
41. Grambow, B. and Giffaut, E. (2006) Coupling of chemical processes in the near field. Scientific Basis for Nuclear Waste Management XXIX, 932, 55-66.
42. 4. Journal of Alloys and Compounds, 390, 112-114.
43. Haaker, R.F. and Ewing, R.C. (1981) Solution-gelation method for preparing polycrystalline zircon. Journal of the American Ceramic Society, 64, C149-C149.
44. Halden, N.M., Hawthorne, F.C., Campbell, J.L., Teesdale, W.J., Maxwell, J.A., and Higuchi, D. (1993) Chemical characterization of oscillatory zoning and overgrowths in zircon using 3 MeV micro-PIXE. Canadian Mineralogist, 31, 637-647.
45. Hanchar, J.M., Finch, R.J., Hoskin, P.W.O., Watson, E.B., Cherniak, D.J., and Mariano, A.N. (2001) Rare earth elements in synthetic zircon: Part 1. synthesis, and rare earth element and phosphorus doping. American Mineralogist, 86, 667-680.
46. 4, doped with Pu-238. Scientific Basis for Nuclear Waste Management XXVI, 757, 215-225.
47. Hanchar, J.M., Burakov, B.E., Zamoryanskaya, M.V., Garbuzov, V.M., Kitsay, A.A., and Zirlin, V.A. (2004) Investigation of Pu incorporation into zircon single crystal. Scientific Basis for Nuclear Waste Management XXVIII, 824, 225-229.
48. Harley, S.L. and Kelly, N.M. (2007) Zircon-tiny but timely. Elements, 3, 13-18.
49. Harlov, D.E., Wirth, R., and Hetherington, C.J. (2007) The relative stability of monazite and huttonite at 300-900 C and 200-1000 MPa: Metasomatism and the propagation of metastable mineral phases. American Mineralogist, 92, 1652-1664.
50. Hawkesworth, C.J. and Kemp, A.I.S. (2006) Using hafnium and oxygen isotopes in zircons to unravel the record of crustal evolution. Chemical Geology, 226, 144-162.
51. 2. Contributions to Mineralogy and Petrology, 30, 72-83.
52. Hess, N.J., Weber, W.J., and Conradson, S.D. (1998a) U and Pu Liii XAFS of Pu-doped glass and ceramic waste forms. Journal of Alloys and Compounds, 271, 240-243.
53. - (1998b) X-ray absorption fine structure of aged, Pu-doped glass and ceramic waste forms. Journal of Nuclear Materials, 254, 175-184.
54. Hinton, R.W. and Upton, B.G.J. (1991) The chemistry of zircon: Variations within and between large crystals from syenite and alkali basalt xenoliths. Geochimica et Cosmochimica Acta, 55, 3287-3302.
55. Holley, C.E., Mulford, R.N., Huber, E.J., Head, E.L., Ellinger, F.H., and Bjorklund, C.W. (1958) Thermodynamics and phase relationships for plutonium oxides. Proceedings of the 2nd United Nations International Conference for the Peaceful Uses of Atomic Energy, 6, 215.
56. Hoskin, P.W.O. and Schaltegger, U. (2003) The composition of zircon and igneous and metamorphic petrogenesis. In J.M. Hanchar and P.W.O. Hoskin, Eds., Zircon, 53, p. 27-55. Reviews in Mineralogy and Geochemistry, Mineralogical Society of America, Chantilly, Virginia.
57. Hoskin, P.W.O., Kinny, P.D., Wyborn, D., and Chappell, B.W. (2000) Identifying accessory mineral saturation during differentiation in granitoid magmas: an integrated approach. Journal of Petrology, 41, 1365-1396.
58. Janeczek, J. (1991) Composition and origin of coffinite from Jachymov, Czechoslovakia. Neues Jahrbuch für Mineralogie, 9, 385-395.
59. 2 under reducing conditions. Scientific Basis for Nuclear Waste Management XX, 257, 497-504.
60. - (1992b) Dissolution and alteration of uraninite under reducing conditions. Journal of Nuclear Materials, 190, 157-173.
61. Johnson, G.K., Van Deventer, E.H., Kruger, O.L., and Hubbard, W.N. (1969) The enthalpies of formation of plutonium dioxide and plutonium mononitride. The Journal of Chemical Thermodynamics, 1, 89-98.
62. Keller, C. (1963) Untersuchung der germanate und silikate des typs ABO4 der vierwertigen elemente thorium bis americium. Nukleotik, 5, 41-48.
63. 2 in a MOX fuel development. Journal of Nuclear Materials, 378, 98-104.
64. Kleykamp, H. (1999) Selection of materials as diluents for burning of plutonium fuels in nuclear reactors. Journal of Nuclear Materials, 275, 1-11.
65. 4. The Journal of Chemical Thermodynamics, 40, 931-934.
66. Levien, L., Prewitt, C.T., and Weidner, D.J. (1980) Structure and elastic properties of quartz at pressure. American Mineralogist, 65, 920-930.
67. Levin, E.M. and McMurdie, H.F. (1975) Phase Diagrams for Ceramists, 513 p. Supplement, American Ceramic Society, Columbus, Ohio.
68. Lumpkin, G.R. (2006) Ceramic waste forms for actinides. Elements, 2, 365-372.
69. Lumpkin, G.R. and Chakoumakos, B.C. (1988) Chemistry and radiation effects of thorite-group minerals from the Harding pegmatite, Taos County, New Mexico. American Mineralogist, 73, 1405-1419.
70. 4 and enthalpy of the thorite → huttonite phase transition. Geochimica et Cosmochimica Acta, 69, 4675-4683.
71. 2). Acta Crystallographica, 12, 507-511.
72. Meis, C. and Gale, J.D. (1998) Computational study of tetravalent uranium and plutonium lattice diffusion in zircon. Materials Science and Engineering: B, 57, 52-61.
73. Meldrum, A., Zinkle, S.J., Boatner, L.A., and Ewing, R.C. (1998) A transient liquid-like phase in the displacement cascades of zircon, hafnon and thorite. Nature, 395, 56-58.
74. - (1999) Heavy-ion irradiation effects in the ABO4 orthosilicates: Decomposition, amorphization, and recrystallization. Physical Review B, 59, 3981-3992.
75. Mumpton, F.A. and Roy, R. (1961) Hydrothermal stability studies of the zircon-thorite group. Geochimica et Cosmochimica Acta, 21, 217-238.
76. Myers, E.R. (1998) A statistical-mechanics model of ordering in aluminosilicate solid solutions. Physics and Chemistry of Minerals, 25, 465-468.
77. Naher, S. and Haseeb, A. (2008) Production and purification of zircon opacifier from zircon found in the coastal area of Bangladesh. Journal of Materials Processing Technology, 205, 203-206.
78. O'Neill, H.St.C. (2006) Free energy of formation of zircon and hafnon. American Mineralogist, 91, 1134-1141.
79. Pagel, M. (1982) The mineralogy and geochemistry of uranium, thorium, and rare-earth elements in two radioactive granites of the Vosges, France. Mineralogical Magazine, 46, 149-161.
80. Palin, E.J. and Harrison, R.J. (2007) A Monte Carlo investigation of the thermodynamics of cation ordering in 2-3 spinels. American Mineralogist, 92, 1334-1345.
81. Pepin, J.G., Vance, E.R., and McCarthy, G.J. (1981) The crystal-chemistry of cerium in the monazite structure-type phase of tailored-ceramic nuclear waste forms. Materials Research Bulletin, 16, 627-633.
82. Plant, J.A., Simpson, P.R., Smith, B., and Windley, B.F. (1999) Uranium ore deposits; products of the radioactive earth. In P.C. Burns, and R.J. Finch, Eds., Uranium: Mineralogy, Geochemistry, and the Environment, 38, p. 255-319. Reviews in Mineralogy and Geochemistry, Mineralogical Society of America, Chantilly, Virginia.
83. Pointeau, V., Deditius, A.P., Miserque, F., Renock, D., Becker, U., Zhang, J., Clavier, N., Dacheux, N., Poinssot, C., and Ewing, R.C. (2009) Synthesis and characterization of coffinite. Journal of Nuclear Materials, 393, 449-458.
84. Pointer, C.M., Ashworth, J.R., and Ixer, R.A. (1988a) The zircon-thorite mineral group in metasomatized granite, Ririwai, Nigeria. 1. Geochemistry and metastable solid-solution of thorite and coffinite. Mineralogy and Petrology, 38, 245-262.
85. - (1988b) The zircon-thorite mineral group in metasomatized granite, Ririwai, Nigeria. 2. Zoning, alteration, and exsolution in zircon. Mineralogy and Petrology, 39, 21-37.
86. 4. Physical Review B, 39, 6388-6394.
87. Pollok, K., Jamtveit, B., and Putnis, A. (2001) Analytical transmission electron microscopy of oscillatory zoned grandite garnets. Contributions to Mineralogy and Petrology, 141, 358-366.
88. 8. Soviet Journal of Atomic Energy, 2, 439-443.
89. Ramakrishnan, S.S., Gokhale, K.V.G., and Subbarao, E.C. (1969) Solid solubility in system zircon-hafnon. Materials Research Bulletin, 4, 323-328.
90. Richardson, S.W., Gilbert, M.C., and Bell, P.M. (1969) Experimental determination of kyanite-andalusite and andalusite-sillimanite equilibria-aluminum silicate triple point. American Journal of Science, 267, 259-272.
91. Robertson, J. (2000) Band offsets of wide-band-gap oxides and implications for future electronic devices. Journal of Vacuum Science and Technology B, 18, 1785-1791.
92. Robie, R.A., Hemingway, B.S., and Fisher, J.R. (1979) Thermodynamic properties of minerals and related substances at 298.15 K and 1 bar (105 pascals) pressure and at higher temperatures. U.S. Geological Survery Bulletin, 1452, 456.
93. Robinson, K., Gibbs, G.V., and Ribbe, P.H. (1971) The structure of zircon: a comparison with garnet. American Mineralogist, 56, 782-790.
94. Robit-Pointeau, V., Poinssot, C., Vitorge, P., Grambow, B., Cui, D., Spahiu, K., and Catalette, H. (2006) Assessment of the relevance of coffinite formation within the near-field environment of spent nuclear fuel geological disposals. Scientific Basis for Nuclear Waste Management XXIX, 932, 114.
95. Romans, P.A., Brown, L.L., and White, J.C. (1975) Electron-microprobe study of yttrium, rare-earth, and phosphorus distribution in zoned and ordinary zircon. American Mineralogist, 60, 475-480.
96. Ruh, R. and Corfield, P.W. (1970) Crystal structure of monoclinic hafnia and comparison with monoclinic zirconia. Journal of the American Ceramic Society, 53, 126-129.
97. Sanchez, J.M., Ducastelle, F., and Gratias, D. (1984) Generalized cluster description of multicomponent systems. Physica A, 128, 334-350.
98. Scherer, E.E., Whitehouse, M.J., and Munker, C. (2007) Zircon as a monitor of crustal growth. Elements, 3, 19-24.
99. Shannon, R.D. (1976) Revised effective ionic-radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica, A32, 751-767.
100. Shein, I.R., Shein, K.I., and Ivanovskii, A.L. (2006) Thorite versus huttonite: Stability, electronic properties, and X-ray emission spectra from first-principle calculations. Physics and Chemistry of Minerals, 33, 545-552.
101. Sirdeshmukh, D.B. and Subhadra, K.G. (1975) Elastic properties of zircon. Journal of Applied Physics, 46, 3681-3682.
102. 2. Powder Diffraction, 15, 234-238.
103. Smits, G. (1989) (U, Th)-bearing silicates in reefs of the Witwatersrand, South-Africa. Canadian Mineralogist, 27, 643-655.
104. Speer, J.A. (1980a) The actinide orthosilicates. In P.H. Ribbe, Ed. Orthosilicates, 5, p. 113-135. Reviews in Mineralogy, Mineralogical Society of America, Chantilly, Virginia.
105. - (1980b) Zircon. In P.H. Ribbe, Ed., Orthosilicates, 5, p. 67-112. Reviews in Mineralogy, Mineralogical Society of America, Chantilly, Virginia.
106. 4, comparison with zircon and the actinide orthosilicates. American Mineralogist, 67, 804-808.
107. Subbarao, E.C. (1990) Thermal-expansion of compounds of zircon structure. Journal of the American Ceramic Society, 73, 1246-1252.
108. 4 polymorphs: huttonite and thorite. Acta Crystallographica, B34, 1074-1079.
109. Uher, P. and Cerny, P. (1998) Zircon in hercynian granitic pegmatites of the Western Carpathians, Slovakia. Geologica Carpathica, 49, 261-270.
110. Ushakov, S.V., Burakov, B.E., Garbuzov, V.M., Anderson, E.B., Strykanova, E.E., Yagovkina, M.M., Helean, K.B., Guo, Y.X., Ewing, R.C., and Lutze, W. (1998) Synthesis of Ce-doped zircon by a sol-gel process. Scientific Basis for Nuclear Waste Management XXI, 506, 281-288.
111. Ushakov, S.V., Gong, W., Yagovkina, M.M., Helean, K.B., Lutze, W., and Ewing, R.C. (1999) Solid solutions of Ce, U, and Th in zircon. Environmental Issues and Waste Management Technologies in the Ceramic and Nuclear Industries IV, 93, 357-363.
112. Vance, E.R. (1994) Synroc-a suitable waste form for actinides. Materials Research Society Bulletin, 19, 28-32.
113. Vinograd, V.L., Sluiter, M.H.F., Winkler, B., Putnis, A., Halenius, U., Gale, J.D., and Becker, U. (2004) Thermodynamics of mixing and ordering in pyrope-grossular solid solution. Mineralogical Magazine, 68, 101-121.
114. 3 system predicted from the excess enthalpies of supercell structures with single and double defects. Physical Review B, 79, 104201.
115. Warren, M.C., Dove, M.T., Myers, E.R., Bosenick, A., Palin, E.J., Sainz-Diaz, C.I., Guiton, B.S., and Redfern, S.A.T. (2001) Monte Carlo methods for the study of cation ordering in minerals. Mineralogical Magazine, 65, 221-248.
116. Weber, W.J. (1990) Radiation-induced defects and amorphization in zircon. Journal of Materials Research, 5, 2687-2697.
117. - (1991) Self-radiation damage and recovery in Pu-doped zircon. Radiation Effects and Defects in Solids, 115, 341-349.
118. Weber, W.J., Ewing, R.C., and Wang, L.M. (1994) The radiation-induced crystalline-to-amorphous transition in zircon. Journal of Materials Research, 9, 688-698.
119. Weber, W.J., Ewing, R.C., and Lutze, W. (1996) Performance assessment of zircon as a waste form for excess weapons plutonium under deep borehole burial conditions. Scientific Basis for Nuclear Waste Management XIX, 412, 25-32.
120. Weber, W.J., Ewing, R.C., Catlow, C.R.A., de la Rubia, T.D., Hobbs, L.W., Kinoshita, C., Matzke, H., Motta, A.T., Nastasi, M., Salje, E.K.H., Vance, E.R., and Zinkle, S.J. (1998) Radiation effects in crystalline ceramics for the immobilization of high-level nuclear waste and plutonium. Journal of Materials Research, 13, 1434-1484.
121. Wilk, G.D. and Wallace, R.M. (1999) Electrical properties of hafnium silicate gate dielectrics deposited directly on silicon. Applied Physics Letters, 74, 2854-2856.
122. Wilk, G.D., Wallace, R.M., and Anthony, J.M. (2000) Hafnium and zirconium silicates for advanced gate dielectrics. Journal of Applied Physics, 87, 484-492.
123. 4+ substitutions in zircon. Journal of Nuclear Materials, 278, 207-211.
124. Wyckoff, R.W.G. (1963) Crystal Structures 1. Interscience Publishers, New York.
125. Xu, H.F. and Wang, Y.F. (1999) Electron energy-loss spectroscopy (EELS) study of oxidation states of Ce and U in pyrochlore and uraninite: natural analogues for Pu- and U-bearing waste forms. Journal of Nuclear Materials, 265, 117-123.
126. Yeomans, J.M. (1992) Statistical mechanics of phase transitions, 164 p. Oxford Science Publications, Clarendon Press, Oxford.
127. Zinner, E. and Crozaz, G. (1986) A method for the quantitative measurement of rare-earth elements in the ion microprobe. International Journal of Mass Spectrometry and Ion Processes, 69, 17-38.
128. Dove, M.T. (1999) Order/disorder phenomena in minerals: ordering phase transitions and solid solutions. In K. Wright and R. Catlow, Eds., Microscopic Properties and Processes in Minerals, C543, p. 451-475. NATO Science Series, Kluwer Academic Publishers, Dordrecht.
129. Finch, R.J., Hanchar, J.M., Hoskin, P.W.O., and Burns, P.C. (2001) Rare-earth elements in synthetic zircon: Part 2. A single-crystal X-ray study of xenotime substitution. American Mineralogist, 86, 681-689.