TY - JOUR
T1 - Accumulation of radiation damage and disordering in MgAl2O 4 under swift heavy ion irradiation
AU - Yasudaa, Kazuhiro
AU - Yamamotoa, Tomokazu
AU - Etoh, Motoki
AU - Kawasoea, Shinji
AU - Matsumura, Syo
AU - Ishikawa, Norito
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011
Y1 - 2011
N2 - Accumulation and recovery of radiation-induced damage with swift heavy ions in stoichiometric magnesium aluminate spinel, MgAl2O4, has been investigated. Microstructural change and atomic disordering was examined through transmission electron microscopy (TEM) techniques, with bright-field (BF) and high-resolution (HR) TEM images, and high angular resolution electron channelling X-ray spectroscopy (HARECXS), for single crystal MgAl2O4 irradiated with 200 MeV Xe, and 340 or 350 MeV Au ions. The density of core damage region, detected by BFTEM with Fresnel-contrast, increased proportionally with ion fluence at the early stage of accumulation and saturated at a fluence higher than 1016 ions m-2. This result is discussed with a balance between the formation and recovery of the core damage region under irradiation, and the influence region to induce the recovery was evaluated to be 7-9 nm in radius. HARECXS and electron diffraction analysis revealed that cations at tetrahedral sites preferentially occupy octahedral sites to transform to defective rock-salt structure. The structure of the core damage region is found from HR and BFTEM images to be a columnar vacancy-rich region with a low atomic density.
AB - Accumulation and recovery of radiation-induced damage with swift heavy ions in stoichiometric magnesium aluminate spinel, MgAl2O4, has been investigated. Microstructural change and atomic disordering was examined through transmission electron microscopy (TEM) techniques, with bright-field (BF) and high-resolution (HR) TEM images, and high angular resolution electron channelling X-ray spectroscopy (HARECXS), for single crystal MgAl2O4 irradiated with 200 MeV Xe, and 340 or 350 MeV Au ions. The density of core damage region, detected by BFTEM with Fresnel-contrast, increased proportionally with ion fluence at the early stage of accumulation and saturated at a fluence higher than 1016 ions m-2. This result is discussed with a balance between the formation and recovery of the core damage region under irradiation, and the influence region to induce the recovery was evaluated to be 7-9 nm in radius. HARECXS and electron diffraction analysis revealed that cations at tetrahedral sites preferentially occupy octahedral sites to transform to defective rock-salt structure. The structure of the core damage region is found from HR and BFTEM images to be a columnar vacancy-rich region with a low atomic density.
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U2 - 10.3139/146.110564
DO - 10.3139/146.110564
M3 - Article
AN - SCOPUS:80053375024
VL - 102
SP - 1082
EP - 1088
JO - International Journal of Materials Research
JF - International Journal of Materials Research
SN - 1862-5282
IS - 9
ER -