Ion irradiation-induced amorphization and nano-crystal formation in garnets
Journal
Journal of Nuclear Materials
Journal Volume
303
Journal Issue
2-3
Start Page
177
End Page
187
ISSN
0022-3115
Date Issued
2002-06
Author(s)
Abstract
The radiation susceptibility of garnet structure types (A3B2(XO4)3, Ia3d, Z = 8) has been examined by 1.0 MeV Kr2+ irradiation with in situ transmission electron microscopy over the temperature range of 50-1070 K. The target garnets included five natural garnets: almandine, andradite, pyrope, grossular and spessartine, and five synthetic garnets incorporating various contents of actinides. The synthetic garnets were silicates (N-series) and ferrate-aluminates (G-series). The critical amorphization temperature (Tc), above which amorphization does not occur, were determined to be 1050 K for N77, 1130 K for N56, 1100 K for G3, 890 K for G4 and 1030 K for andradite. Tc of the synthetic garnets increased with increasing mass density of the target and as the electronic-to-nuclear stopping power ratio decreased. During ion irradiation of the G3 garnet at a temperature of 1023 K near the Tc, nano-crystals were produced in which the unit-cell parameter of the original garnet was halved (∼0.64 nm) as a result of a radiation-induced recrystallization process, without evidence for ordering of the cations.
Subjects
Amorphization
Crystallization
Crystals
High temperature effects
Ion bombardment
Nanostructured materials
Positive ions
Radiation effects
Targets
Transmission electron microscopy
Ion irradiations
Radiation susceptibilies
Garnets
Publisher
Elsevier BV
Type
journal article