Studies of interaction between He and elements with mass number 140 in Fe by time-differential perturbed-angular-correlation measurements |
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Authors: | Yoshitaka Ohkubo Akihiro Taniguchi Qiu Xu Minoru Tanigaki Koichi Sato |
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Institution: | 1. Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japanohkubo@rri.kyoto-u.ac.jp;3. Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan |
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Abstract: | Room-temperature time-differential perturbed-angular-correlation (TDPAC) spectra of 140Ce arising through 140Ba-140La from 140Cs in He-doped Fe, unannealed and annealed in vacuum at various temperatures, were obtained in order to examine whether Ce (or rather, La and Ba) and He form complexes having a definite geometrical structure in Fe, as suggested by first-principles density-functional theory calculations. No clear signal of such complexes was observed in the TDPAC spectra. However, the TDPAC spectra indicate that Ce and He form complexes having a variety of geometrical structures. Comparison with reported TDPAC results on 111Cd arising from 111In in He-doped stainless steel shows that the parent atoms (La and Ba) of 140Ce trap He atoms more efficiently than In atoms do, indicating stronger bonding of He to the former atoms, while different from the present case, 111Cd (In)–He complexes form a unique geometrical structure. |
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Keywords: | He Ce ion implantation Fe defects TDPAC spectra |
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