Displacive radiation effects in the monazite- and zircon-structure orthophosphates

Journal Article · Sun Nov 30 23:00:00 EST 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.13805· OSTI ID:550514

Meldrum, A ^[1]; Boatner, L A ^[2]; Ewing, R C ^[1]

---

1. Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131-1116 (United States)
2. Oak Ridge National Laboratory, Oak Ridge, Tennesee 37831-6056 (United States)

Monazite-structure orthophosphates, including LaPO{sub 4}, PrPO{sub 4}, NdPO{sub 4}, SmPO{sub 4}, EuPO{sub 4}, GdPO{sub 4}, and natural monazite, and their zircon-structure analogs, including ScPO{sub 4}, YPO{sub 4}, TbPO{sub 4}, TmPO{sub 4}, YbPO{sub 4}, and LuPO{sub 4}, were irradiated by 800keVKr{sup 2+} ions in the temperature range of 20 to 600 K. The critical amorphization dose was determined {ital in situ} as a function of temperature using selected-area electron diffraction. Amorphization doses were in the range of 10{sup 14} to 10{sup 16}ions/cm{sup 2}, depending on the temperature. Materials with the zircon structure were amorphized at higher temperatures than those with the monazite structure. The critical amorphization temperature ranged from 350 to 485 K for orthophosphates with the monazite structure and from 480 to 580 K for those with the zircon structure. However, natural zircon (ZrSiO{sub 4}) can be amorphized at over 1000 K. Within each structure type, the critical temperature of amorphization increased with the atomic number of the lanthanide cation. Structural topology models are consistent with the observed differences between the two structure types, but do not predict the relative amorphization doses for different compositions. The ratio of electronic-to-nuclear stopping correlates well with the observed sequence of susceptibility to amorphization within each structure type, consistent with previous results that electronic-energy losses enhance defect recombination in the orthophosphates. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 550514
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 21 Vol. 56; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ELECTRON DIFFRACTION
EUROPIUM COMPOUNDS
GADOLINIUM COMPOUNDS
KEV RANGE 100-1000
KRYPTON IONS
LANTHANUM COMPOUNDS
LUTETIUM COMPOUNDS
MONAZITES
NEODYMIUM COMPOUNDS
PHOSPHATE MINERALS
PHOSPHATES
PHYSICAL RADIATION EFFECTS
PRASEODYMIUM COMPOUNDS
SAMARIUM COMPOUNDS
SCANDIUM COMPOUNDS
TERBIUM COMPOUNDS
THULIUM COMPOUNDS
YTTERBIUM COMPOUNDS
YTTRIUM ALLOYS
ZIRCON
ZIRCONATES