TY - JOUR
T1 - Electron-beam induced dissociation of dislocation loops in magnesia-alumina ceramics
AU - Yasuda, K.
AU - Kinoshita, C.
N1 - Funding Information:
This work was supported in part by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Encouragement of Young Scientist and TEPCO foundation. A portion of this work was conducted in the HVEM laboratory of Kyushu University.
PY - 2002/5
Y1 - 2002/5
N2 - Kinetics of interstitial-type dislocation loops in α-Al2O3 and MgO · Al2O3, which were induced by 6 keV Ar+ ions at 300 K, has been investigated under electron irradiation at 300-870 K by transmission electron microscopy. Dislocation loops disappeared during electron irradiation at energies of 100, 150 and 200 keV, where displacement damage is hardly induced in α-Al2O3 and MgO · Al2O3 with those electron energies. The disappearing rate of dislocation loops increases with decreasing electron energy and with decreasing irradiation temperature. Further, a portion of dislocation loops in α-Al2O3 has been found to grow under the subthreshold-energy electron irradiation, and the average size of the surviving dislocation loops decreases with irradiation at 300 K but increases at 370, 420 and 570 K. We have reached a conclusion that dislocation loops in α-Al2O3 and MgO · Al2O3 dissociate into isolated interstitials through ionizing radiation. The generated interstitial has been found to mostly recombine with radiation-induced vacancies at lower irradiation temperature (300 K) but to be absorbed to the surviving dislocation loops at higher temperature (370-570 K). The disappearing rate of loops is discussed in terms of a balance between the dissociation process by ionizing radiation and the diffusion process of the generated interstitials.
AB - Kinetics of interstitial-type dislocation loops in α-Al2O3 and MgO · Al2O3, which were induced by 6 keV Ar+ ions at 300 K, has been investigated under electron irradiation at 300-870 K by transmission electron microscopy. Dislocation loops disappeared during electron irradiation at energies of 100, 150 and 200 keV, where displacement damage is hardly induced in α-Al2O3 and MgO · Al2O3 with those electron energies. The disappearing rate of dislocation loops increases with decreasing electron energy and with decreasing irradiation temperature. Further, a portion of dislocation loops in α-Al2O3 has been found to grow under the subthreshold-energy electron irradiation, and the average size of the surviving dislocation loops decreases with irradiation at 300 K but increases at 370, 420 and 570 K. We have reached a conclusion that dislocation loops in α-Al2O3 and MgO · Al2O3 dissociate into isolated interstitials through ionizing radiation. The generated interstitial has been found to mostly recombine with radiation-induced vacancies at lower irradiation temperature (300 K) but to be absorbed to the surviving dislocation loops at higher temperature (370-570 K). The disappearing rate of loops is discussed in terms of a balance between the dissociation process by ionizing radiation and the diffusion process of the generated interstitials.
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U2 - 10.1016/S0168-583X(02)00610-9
DO - 10.1016/S0168-583X(02)00610-9
M3 - Article
AN - SCOPUS:0036574823
VL - 191
SP - 559
EP - 564
JO - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
JF - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
SN - 0168-583X
IS - 1-4
ER -