Alpha-decay-induced fracturing in zircon: the transition from the crystalline to the metamict state

Journal Article · Fri Jun 19 04:00:00 EDT 1987 · Science (Washington, D.C.); (United States)

DOI:https://doi.org/10.1126/science.236.4808.1556· OSTI ID:6297782

Chakoumakos, B C; Murakami, T; Lumpkin, G R; Ewing, R C

A natural single crystal of zircon, ZrSiO4, from Sri Lanka exhibited zonation due to alpha-decay damage. The zones vary in thickness on a scale from one to hundreds of micrometers. The uranium and thorium concentrations vary from zone to zone such that the alpha-decay dose is between 0.2 x 10 W and 0.8 x 10 W alpha-event per milligram (0.15 to 0.60 displacement per atom). The transition from the crystalline to the aperiodic metamict state occurs over this dose range. Differential expansion of individual layers due to variations in their alpha-decay dose caused a systematic pattern of fractures that do not propagate across aperiodic layers. High-resolution transmission electron microscopy revealed a systematic change in the microstructure from a periodic atomic array to an aperiodic array with increasing alpha-decay dose. At doses greater than 0.8 x 10 W alpha-events per milligram there is no evidence for long-range order. This type of damage will accumulate in actinide-bearing, ceramic nuclear waste forms. The systematic pattern of fractures would occur in crystalline phases that are zoned with respect to actinide radionuclides.

• Research Organization: Univ. of New Mexico, Albuquerque
• DOE Contract Number: FG04-84ER45099
• OSTI ID: 6297782
• Journal Information: Science (Washington, D.C.); (United States), Journal Name: Science (Washington, D.C.); (United States) Vol. 236; ISSN SCIEA
• Country of Publication: United States
• Language: English

Related Subjects

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360206* -- Ceramics
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ACTINIDES
ALPHA PARTICLES
CHARGED PARTICLES
DATA
DISTRIBUTION
ELEMENTS
EXPERIMENTAL DATA
INFORMATION
METALS
METAMICT STATE
MINERALS
NUMERICAL DATA
OXYGEN COMPOUNDS
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SPATIAL DISTRIBUTION
THORIUM
TRANSITION ELEMENT COMPOUNDS
URANIUM
ZIRCON
ZIRCONIUM COMPOUNDS
ZIRCONIUM SILICATES