Radiation-Induced Amorphization

### History and applications The earliest description of a change in mineral property caused by radiation-damage was by Jons Jacob Berzelius in 1814. Berzelius, a Swedish physician and mineral chemist, was certainly one of the most eminent scientists of his century, discovering the elements cerium, selenium and thorium. He discovered that some U- and Th-bearing minerals glowed on moderate heating, releasing, sometimes violently, large amounts of energy. This “pyrognomic” behavior was first observed in gadolinite, (REE)2FeBe2Si2O10, as it released stored energy. Today, this same type of catastrophic energy release is a significant concern in reactor safety where rapid energy release from neutron-irradiated graphite can lead to a rise in temperature and the rupture of fuel elements. In 1893, Brogger defined “metamikte” in an encyclopedia entry for amorphous materials. Metamict minerals were believed to have been previously crystalline, as judged by well-formed crystal faces, but had a characteristic glass-like, conchoidal fracture and were optically isotropic. Prior to the discovery of radioactivity by Becquerel in 1896, the metamict state was not recognized as a radiation-induced transformation. Hamberg (1914) was the first to suggest that metamictization is a radiation-induced, periodic-to-aperiodic transformation caused by α-particles that originate from the constituent radionuclides in the uranium and thorium decay-series. A detailed summary of the history of studies of radiation effects in minerals can be found in Ewing (1994). In the 1950s, interest in metamict minerals was revived. Adolf Pabst rescued the term “metamict” from obscurity in his presidential address to the Mineralogical Society of America in 1951 (Pabst 1952). However, mineralogists paid limited attention to nuclear effects in minerals or the general importance of radiation effects in modifying the properties of materials. By the early 1940s, E.P. Wigner already had anticipated that the intense neutron flux in the Hanford Production reactors …

[1]  J. McCallum,et al.  Hardness and elastic modulus of zircon as a function of heavy-particle irradiation dose:: II. Pb-ion implantation damage , 1994 .

[2]  Roger Kelly,et al.  Criteria for bombardment-induced structural changes in non-metallic solids , 1975 .

[3]  R. Ewing,et al.  Alpha-recoil damage in titanite (CaTiSiO_5): Direct observation and annealing study using high resolution transmission electron microscopy , 1991 .

[4]  J. A. Speer.  The actinide orthosilicates , 1980 .

[5]  J. Brinkman.  On the Nature of Radiation Damage in Metals , 1954 .

[6]  William J. Weber,et al.  Self-radiation damage in Gd2Ti2O7 , 1985 .

[7]  Steven J. Zinkle,et al.  Radiation effects in crystalline ceramics for the immobilization of high-level nuclear waste and plutonium , 1998 .

[8]  L. Cartz,et al.  Heavy ion bombardment of monoclinic thsio4, tho2 and monazite , 1981 .

[9]  W. Weber,et al.  Transmission electron microscopy study of ion-beam-induced amorphization of Ca2La8(SiO4)6O2 , 1999 .

[10]  F. Farges,et al.  The structure of aperiodic, metamict (Ca, Th)ZrTi_2O_7 (zirconolite): An EXAFS study of the Zr, Th, and U sites , 1993 .

[11]  M. Robinson.  Computer Simulation of Atomic Collision Processes in Solids , 1992 .

[12]  S. D. Roh,et al.  Ion implantation in Al/sub x/Ga/sub 1-x/As: damage structures and amorphization mechanisms , 1998 .

[13]  R. Fleischer,et al.  Nuclear tracks in solids. , 1980, Scientific American.

[14]  R. Ewing,et al.  Cross-sectional transmission electron microscopy study of 1.5 MeV Kr+ irradiation-induced amorphization in α-quartz , 1998 .

[15]  J. Coleman,et al.  On the amorphization process in Al0.6Ga0.4As/GaAs heterostructures , 1998 .

[16]  M. Nastasi,et al.  Radiation Damage Effects in Zirconia. , 1999 .

[17]  R. Ewing,et al.  An X-ray Absorption Spectroscopy Investigation of the Ta Site in Alpha-Recoil Damaged Natural Pyrochlores , 1986 .

[18]  L. Nasdala,et al.  Heterogeneous metamictization of zircon on a microscale , 1996 .

[19]  Katherine L. Smith,et al.  Determination of 25 elements in the complex oxide mineral zirconolite by analytical electron microscopy , 1994 .

[20]  M. Nastasi,et al.  Structure and mechanical properties of irradiated magnesium aluminate spinel , 1996 .

[21]  A. Hamberg.  Die radioaktiven Substanzen und die geologische Forschung , 1913 .

[22]  J. F. Gibbons,et al.  Ion implantation in semiconductors—Part II: Damage production and annealing , 1972 .

[23]  M. Nastasi,et al.  Ion beam analysis of MgAl2O4 spinel irradiated with fast neutrons to 50–250 dpa , 1996 .

[24]  R. Ewing.  The crystal chemistry of complex niobium and tantalum oxides. IV. The metamict state: Discussion , 1975 .

[25]  S. Zinkle,et al.  Effects of dose rate and temperature on the crystalline-to-metamict transformation in the ABO 4 orthosilicates , 1999 .

[26]  Gong,et al.  Surface and grain-boundary amorphization: Thermodynamic melting of coesite below the glass transition temperature. , 1996, Physical review. B, Condensed matter.

[27]  W. J. Weber,et al.  Self-radiation damage and recovery in Pu-doped zircon , 1991 .

[28]  H. Tan,et al.  Ion damage buildup and amorphization processes in GaAs–AlxGa1−xAs multilayers , 1996 .

[29]  William J. Weber,et al.  Effects of self-radiation damage in Cm-doped Gd2Ti2O7 and CaZrTi2O7 , 1986 .

[30]  G. Parodi,et al.  Monazite-huttonite solid-solutions from the Vico Volcanic Complex, Latium, Italy Monazite-huttonite solid-solutions from the Vico Volcanic Complex, Latium, Italy , 1996, Mineralogical Magazine.

[31]  William L. Johnson,et al.  Crystal-to-glass transformation in metallic materials☆ , 1988 .

[32]  F. Olmi,et al.  Radiation damage in zircons , 1997 .

[33]  R. Ewing,et al.  Amorphization of zirconolite: alpha-decay event damage versus krypton ion irradiation , 1992 .

[34]  W. C. Butterman,et al.  Zircon Stability and the Zr02-Si02 Phase Diagram , 1967 .

[35]  C. Frondel.  Hydroxyl substitution in thorite and zircon , 1953 .

[36]  Katherine L. Smith,et al.  In situ studies of ion irradiated zirconolite, pyrochlore and perovskite , 1997 .

[37]  R. Ewing,et al.  Energetics of radiation damage in natural zircon (ZrSiO4) , 1994 .

[38]  Effects of Ion Dose and Irradiation Temperature on the Microstructure of Three Spinel Compositions , 1994 .

[39]  R. Ewing,et al.  A comparison of radiation effects in crystalline ABO4 -type phosphates and silicates , 2000, Mineralogical Magazine.

[40]  E. Salje,et al.  Is “metamictization” of zircon a phase transition? , 1999 .

[41]  R. Ewing,et al.  The Metamict State , 1987 .

[42]  T. Payne,et al.  Investigation of the long-term performance of betafite and zirconolite in hydrothermal veins from Adamello, Italy , 1999 .

[43]  Structure and property changes in spinel irradiated with heavy ions , 1997 .

[44]  R. Ewing,et al.  Alpha-recoil damage in zirconolite (CaZrTi_2O_7) , 1986 .

[45]  Bryan C. Chakoumakos,et al.  Crystal Chemical Constraints on the Formation of Actinide Pyrochlores , 1984 .

[46]  S. Zinkle,et al.  Heavy-ion irradiation effects in the ABO{sub 4} orthosilicates: Decomposition, amorphization, and recrystallization , 1999 .

[47]  R. Ewing,et al.  The amorphization of complex silicates by ion-beam irradiation , 1992 .

[48]  J. Ziegler,et al.  stopping and range of ions in solids , 1985 .

[49]  B. W. Anderson,et al.  Study of metamict Ceylon zircons , 1972, Mineralogical Magazine.

[50]  D. Pedraza.  Mechanisms of the electron irradiation-induced amorphous transition in intermetallic compounds , 1986 .

[51]  W. J. Weber,et al.  Zircon: A host-phase for the disposal of weapons plutonium , 1995 .

[52]  R. Ewing,et al.  Ion Irradiation Effects for Two Pyrochlore Compositions: Gd 2 Ti 2 O 7 and Gd 2 Zr 2 0 7 , 1998 .

[53]  W. Miehle,et al.  Amorphization of metallic alloys by ion bombardment , 1993 .

[54]  W. Bolse.  Formation and development of disordered networks in Si-based ceramics under ion bombardment , 1998 .

[55]  A. E. Ringwood,et al.  Alpha-recoil damage in natural zirconolite and perovskite. , 1981 .

[56]  William J. Weber,et al.  Performance assessment of zircon as a waste form for excess weapons plutonium under deep borehole burial conditions , 1995 .

[57]  M. Nastasi,et al.  Cation disorder in high-dose, neutron-irradiated spinel , 1995 .

[58]  F. Farges.  The structure of metamict zircon: A temperature-dependent EXAFS study , 1994 .

[59]  R C Ewing,et al.  Nuclear waste forms for actinides. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[60]  R. Ewing,et al.  The metamict state: Implications for radiation damage in crystalline waste forms☆☆☆ , 1980 .

[61]  R. Ewing,et al.  Ion irradiation effects in nonmetals: formation of nanocrystals and novel microstructures , 2000 .

[62]  W. J. Weber,et al.  Radiation damage in zircon and monazite , 1998 .

[63]  R. Ewing,et al.  Ion-beam induced disordering and onset of amorphization in spinel by defect accumulation , 1995 .

[64]  R. Ewing,et al.  Ion Beam-Induced Amorphization of (Mg, Fe) 2 SiO 4 Olivine Series: An In Situ Transmission Electron Microscopy Study , 1991 .

[65]  G. Lumpkin.  Rare-element mineralogy and internal evolution of the Rutherford #2 Pegmatite, Amelia County, Virginia; a classic locality revisited , 1998 .

[66]  G. W. Arnold,et al.  Dose-dependence of Pb-ion implantation damage in zirconolite, hollandite, and zircon , 1981 .

[67]  A. Pabst.  HUTTONITE, A NEW MONOCLINIC THORIUM SILICATE , 1951 .

[68]  Rodney C. Ewing,et al.  Radioactive Waste Forms for the Future , 1988 .

[69]  R. J. Ellis,et al.  ADVANCED CANDU SYSTEMS FOR PLUTONIUM DESTRUCTION , 1997 .

[70]  R. Ewing,et al.  Alpha-Decay—Induced Fracturing in Zircon: The Transition from the Crystalline to the Metamict State , 1987, Science.

[71]  Katherine L. Smith,et al.  Application of analytical electron microscopy to the study of radiation damage in the complex oxide mineral zirconolite , 1997 .

[72]  R. Devanathan,et al.  Native vacancy migrations in zircon , 1999 .

[73]  Bryan C. Chakoumakos,et al.  Systematics of the pyrochlore structure type, ideal A2B2X6Y , 1984 .

[74]  Steven J. Zinkle,et al.  Effect of irradiation spectrum on the microstructural evolution in ceramic insulators , 1995 .

[75]  A. Motta,et al.  Theory of electron-irradiation-induced amorphization , 1990 .

[76]  R. Ewing,et al.  Ion beam induced amorphization of monazite , 1996 .

[77]  Mark T. Robinson,et al.  Basic physics of radiation damage production , 1994 .

[78]  C. Degueldre,et al.  Basic Properties of a Zirconia-Based Fuel Material for Light Water Reactors , 1998 .

[79]  R. Ewing,et al.  Image simulation of partially amorphous materials , 1993 .

[80]  F. Clinard.  Review of self-irradiation effects in Pu-substituted zirconolite , 1985 .

[81]  R. Ewing,et al.  Ion beam-induced amorphization in MgO–Al2O3–SiO2. II. Empirical model , 1998 .

[82]  G. Carter,et al.  Defect accumulation during room temperature N+ irradiation of silicon , 1996 .

[83]  W. Compston,et al.  Ion microprobe identification of 4,100–4,200 Myr-old terrestrial zircons , 1983, Nature.

[84]  R. Roy,et al.  Effectiveness of Shearing Stresses in Accelerating Solid Phase Reactions at Low Temperatures and High Pressures , 1962, The Journal of Geology.

[85]  L. Hobbs.  Topology and geometry in the irradiation-induced amorphization of insulators , 1994 .

[86]  Katherine L. Smith,et al.  The relative radiation resistance of zirconolite, pyrochlore and perovskite to 1.5 MeV Kr{sup +} ions , 1997 .

[87]  G. Exarhos.  Induced swelling in radiation damaged ZrSiO4 , 1984 .

[88]  D. Cowgill,et al.  Ion nitriding of titanium alpha plus beta alloy for fusion reactor applications , 1998 .

[89]  Mark T. Robinson,et al.  Computer simulation of collision cascades in monazite , 1983 .

[90]  M. Fleet,et al.  Radiation damage in natural titanite by crystal structure analysis , 1985 .

[91]  R. Ewing,et al.  In situ TEM study of ion-beam-induced amorphization of complex silicate structures , 1990 .

[92]  Michael Nastasi,et al.  Handbook of modern ion beam materials analysis , 1995 .

[93]  L. Hobbs.  Application of Transmission Electron Microscopy to Radiation Damage in Ceramics , 1979 .

[94]  R. Ewing,et al.  Characterization of radiation damage at the Nb site in natural pyrochlores and samarskites by x-ray absorption spectroscopy , 1988 .

[95]  William J. Weber,et al.  Radiation stability of gadolinium zirconate: A waste form for plutonium disposition , 1999 .

[96]  M. Kirk,et al.  Production of amorphous zones in GaAs by the direct impact of energetic heavy ions , 2000 .

[97]  Angel Ibarra,et al.  Optical and dielectric properties of neutron irradiated MgAl2O4 spinels , 1996 .

[98]  William J. Weber,et al.  Models and mechanisms of irradiation-induced amorphization in ceramics , 2000 .

[99]  R S Pease,et al.  REVIEW ARTICLES: The Displacement of Atoms in Solids by Radiation , 1955 .

[100]  R. Bros,et al.  Occurrence of Pu and Fissiogenic REE in Hydrothermal Apatites from the Fossil Nuclear Reactor 16 at Oklo (Gabon) , 1996 .

[101]  R. Ewing,et al.  Effects of ionizing and displacive irradiation on several perovskite-structure oxides , 1998 .

[102]  P. Gupta.  Rigidity, Connectivity, and Glass-Forming Ability , 1993 .

[103]  G. P. Pells.  Radiation-induced electrical conductivity in MgAl2O4 spinel , 1991 .

[104]  R. Ewing,et al.  Metamict minerals: Natural analogues for radiation damage effects in ceramic nuclear waste forms , 1988 .

[105]  W. J. Weber.  Radiation-induced swelling and amorphization in Ca2Nd8(SiO4)6O2 , 1983 .

[106]  B. Chakoumakos,et al.  Chemistry and radiation effects of thorite-group minerals from the Harding Pegmatite, Taos County, New Mexico , 1988 .

[107]  Rodney C. Ewing,et al.  Amorphization of cubic zirconia by caesium-ion implantation , 2000 .

[108]  W. J. Weber,et al.  Radiation-induced defects and amorphization in zircon , 1990 .

[109]  Ming Zhang,et al.  Annealing of -decay damage in zircon: a Raman spectroscopic study , 2000 .

[110]  R. Ewing,et al.  Amorphization in zircon: evidence for direct impact damage , 2000 .

[111]  M. Kirk,et al.  Transmission electron microscopy investigation of the damage produced in individual displacement cascades in GaAs and GaP , 1991 .

[112]  R. Averback,et al.  Fundamental aspects of defect production in solids , 1997 .

[113]  William J. Weber,et al.  XAS and XRD study of annealed 238Pu- and 239Pu-substituted zircons (Zr0.92Pu0.08SiO4) , 2000 .

[114]  R. Ewing,et al.  Electron and ion irradiation of zeolites , 2000 .

[115]  Wang,et al.  Electron-irradiation- and ion-beam-induced amorphization of coesite. , 1996, Physical Review B (Condensed Matter).

[116]  G. Carter,et al.  A phenomenological model of ion-induced crystallization and amorphization , 1991 .

[117]  R. Ewing,et al.  The crystal structures of the ThSiO4 polymorphs: huttonite and thorite , 1978 .

[118]  H. Matzke,et al.  Effects of radiation on microstructure and fracture properties in Ca2Nd8(SiO4)6)2 , 1986 .

[119]  M. Nastasi,et al.  First observation of' amorphization in single-crystal MgA12O4 spinel , 1994 .

[120]  L. Nasdala,et al.  The degree of metamictization in zircon; a Raman spectroscopic study , 1995 .

[121]  R. Ewing,et al.  Alpha-decay damage in minerals of the pyrochlore group , 1988 .

[122]  M. Nastasi,et al.  Ion solid interactions , 1996 .

[123]  Caro,et al.  Evidence of amorphization in molecular-dynamics simulations on irradiated intermetallic NiAl. , 1995, Physical review. B, Condensed matter.

[124]  R. Ewing,et al.  Electron-irradiation-induced phase segregation in crystalline and amorphous apatite: A TEM study , 1997 .

[125]  R. Mccauley.  Structural characteristics of pyrochlore formation , 1980 .

[126]  M Zhang,et al.  Alpha-decay damage and recrystallization in zircon: evidence for an intermediate state from infrared spectroscopy , 2000 .

[127]  C. M. Gramaccioli,et al.  A uranium- and thorium-rich monazite from a South-Alpine pegmatite at Piona, Italy , 1978 .

[128]  D. Gottfried,et al.  The effect of nuclear radiation on the structure of zircon , 1955 .

[129]  D. Cherniak.  Lead diffusion in titanite and preliminary results on the effects of radiation damage on Pb transport , 1993 .

[130]  R. Ewing.  The metamict state: 1993 — the centennial , 1994 .

[131]  P. Ziemann.  Amorphization of metallic systems by ion beams , 1985 .

[132]  Robert M. Hazen,et al.  Crystal structure and compressibility of zircon at high pressure , 1979 .

[133]  L. Cartz,et al.  Differential scanning calorimetry of heavy ion bombarded synthetic monazite , 1983 .

[134]  G. Rossman,et al.  Alpha-decay damage in titanite , 1991 .

[135]  W. J. Weber,et al.  The kinetics of alpha-decay-induced amorphization in zircon and apatite containing weapons-grade plutonium or other actinides , 1997 .

[136]  W. J. Weber,et al.  Radiation effects in nuclear waste forms for high-level radioactive waste , 1995 .

[137]  C. White,et al.  Ion implantation and annealing of crystalline oxides , 1989 .

[138]  W. J. Weber,et al.  Alpha-decay event damage in zircon , 1991 .

[139]  L. Wang.  Applications of advanced electron microscopy techniques to the studies of radiation effects in ceramic materials , 1998 .

[140]  R. Ewing,et al.  Ti-site geometry in metamict, annealed and synthetic complex TiNbTa oxides by X-ray absorption spectroscopy , 1984 .

[141]  N. phil..  II. On the theory of the decrease of velocity of moving electrified particles on passing through matter , 1913 .

[142]  Y. Eyal,et al.  Leaching of uranium and thorium from monazite: I. Initial leaching , 1990 .

[143]  R. Ewing,et al.  Ion beam-induced amorphization in MgO–Al2O3–SiO2. I. Experimental and theoretical basis , 1998 .

[144]  W. Brown.  The many faces of ion beam interactions with insulators , 1988 .

[145]  J. R. Dennis,et al.  Amorphization of silicon by ion implantation: Homogeneous or heterogeneous nucleation? , 1976 .

[146]  S. Zinkle,et al.  Influence of irradiation spectrum and implanted ions on the amorphization of ceramics , 1995 .

[147]  William J. Weber,et al.  The radiation-induced crystalline-to-amorphous transition in zircon , 1994 .

[148]  Fundamental Concepts of Ion-Solid Interactions: Single Ions, 10−12 Seconds , 1992 .

[149]  J. Lindhard,et al.  INTEGRAL EQUATIONS GOVERNING RADIATION EFFECTS. (NOTES ON ATOMIC COLLISIONS, III) , 1963 .

[150]  M. Guinan,et al.  Radiation Effects in SYNROC-D , 1983 .

[151]  K. A. Jackson.  A defect model for ion-induced crystallization and amorphization , 1988 .

[152]  G. Rossman,et al.  Metamict and chemically altered vesuvianite , 1993 .

[153]  D. Peterson,et al.  Self-irradiation effects in 238Pu-substituted zirconolite: II. Effect of damage microstructure on recovery , 1985 .

[154]  R. Ewing,et al.  Detailed in situ study of ion beam-induced amorphization of zircon , 1992 .

[155]  A. Motta.  Amorphization of intermetallic compounds under irradiation - A review , 1997 .

[156]  Niels Bohr,et al.  The penetration of atomic particles through matter , 1948 .

[157]  J. Janeczek,et al.  Annealing of radiation damage in allanite and gadolinite , 1993 .

[158]  Ε. B. Anderson,et al.  High-Uranium Zircon from "Chernobyl Lavas" , 1993 .

[159]  S. Zinkle,et al.  A transient liquid-like phase in the displacement cascades of zircon, hafnon and thorite , 1998, Nature.

[160]  Katherine L. Smith,et al.  The Crystalline-Amorphous Transformation in Natural Zirconolite: Evidence for Long-Term Annealing , 1997 .

[161]  L. Rehn,et al.  Physics of Crystal-to-Glass Transformations , 1999 .

[162]  R. Ewing,et al.  Irradiation-induced nanostructures , 2000 .

[163]  R. Ewing,et al.  An Investigation of Uranium L-Edges of Metamict and Annealed Betafite , 1985 .

[164]  A. Pabst.  The metamict state , 1952 .

[165]  Steven J. Zinkle,et al.  Radiation effects in ceramics , 1994 .

[166]  G. Carter,et al.  Difficulties in deducing disordering mechanisms from experimental studies of disorder-ion fluence functions in ion irradiation of semiconductors , 1979 .

[167]  R. Ewing,et al.  Geochemical alteration of pyrochlore group minerals: Pyrochlore subgroup , 1995 .

[168]  F. Clinard,et al.  Structural damage in a self-irradiated zirconolite-based ceramic , 1984 .

[169]  J. R. Dennis,et al.  Crystalline to amorphous transformation in ion‐implanted silicon: a composite model , 1978 .

[170]  E. Salje,et al.  Thermal annealing of radiation damaged titanite , 1998 .

[171]  A. E. Ringwood,et al.  Immobilisation of high level nuclear reactor wastes in SYNROC , 1979, Nature.

[172]  Steven J. Zinkle,et al.  Defect production in ceramics , 1997 .

[173]  F. Farges,et al.  Structural analysis of radiation damage in zircon and thorite: an X-ray absorption spectroscopic study , 1991 .

[174]  R. Ewing,et al.  Alpha-recoil damage in natural zirconolite (CaZrTi2O7)☆ , 1983 .

[175]  E. Vance,et al.  Radiation damage in natural titanites , 1985 .

[176]  Lumin Wang,et al.  Ion irradiation-induced phase transformation of pyrochlore and zirconolite , 1999 .

[177]  R. Ewing,et al.  Amorphization of ceramic materials by ion beam irradiation , 1998 .

[178]  R. Ewing,et al.  Ion Irradiation-Induced Amorphization in the MgO-Al 2 O 3 -SiO 2 System: A Cascade Quenching Model , 1996 .

[179]  R. Ewing,et al.  Ion-Beam-Induced Amorphization of Complex Ceramic Materials—Minerals , 1992 .

[180]  A. Pabst,et al.  Huttonite, a new monoclinic thorium silicate with an account of its occurrence, analysis, and properties , 1951 .

[181]  J. B. Higgins,et al.  The crystal chemistry and space groups of natural and synthetic titanites , 1976 .

[182]  W. Lutze,et al.  Transmission Electron Microscopy Study of α-Decay Damage in Aeschynite and Britholite , 1996 .

[183]  F. Priolo,et al.  Mechanisms of amorphization in ion implanted crystalline silicon , 1993 .

[184]  F. Morehead,et al.  A model for the formation of amorphous Si by ion bombardment , 1970 .

[185]  G. Rossman,et al.  The metamictization of zircon: Radiation dose-dependent structural characteristics , 1991 .

[186]  P. Tarte,et al.  Metamictization and U-Pb systematics — a study by infrared absorption spectrometry of Precambrian zircons , 1977 .

[187]  R. Ewing,et al.  Temperature dependence of Kr ion-induced amorphization of mica minerals , 1998 .

[188]  Frederick Seitz,et al.  Radiation effects in solids , 1952 .

[189]  R. Roy,et al.  Crystal Chemistry of Pyrochlore , 1962 .

[190]  E. Salje,et al.  Modelling the percolation-type transition in radiation damage , 2000 .

[191]  L. Cartz,et al.  Damage cross-sections of heavy ions in crystal structures , 1982 .

[192]  William J. Weber,et al.  Alpha-decay-induced amorphization in complex silicate structures , 1993 .

[193]  L. Wang,et al.  Effect of temperature and recoil-energy spectra on irradiation-induced amorphization in Ca2La8(SiO4)6O2 , 1994 .