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Fleurence, A.*; Lee, C.-C.*; Friedlein, R.*; Fukaya, Yuki; Yoshimoto, Shinya*; Mukai, Kozo*; Yamane, Hiroyuki*; Kosugi, Nobuhiro*; Yoshinobu, Jun*; Ozaki, Taisuke*; et al.
Physical Review B, 102(20), p.201102_1 - 201102_6, 2020/11
Times Cited Count:2 Percentile:10.32(Materials Science, Multidisciplinary)no abstracts in English
Shimizu, Hirotaka*; Kosugi, Shinya*; Tahara, Yuki*; Yasunaga, Kazufumi*; Kaneta, Yasunori*; Ishikawa, Norito; Hori, Fuminobu*; Matsui, Toshiyuki*; Iwase, Akihiro*
Nuclear Instruments and Methods in Physics Research B, 286, p.291 - 294, 2012/09
Times Cited Count:28 Percentile:86.40(Instruments & Instrumentation)We have studied the magnetic properties of pure CeO irradiated with swift heavy ions. Experiment a results showed that the ferromagnetism was induced even at room temperature by 200 MeV Xe ion irradiation. The value of saturation magnetization, Ms, systematically changes as a function of ion-fluence. The X-ray diffraction (XRD) spectra show that the lattice constant of CeO
increases with increasing ion-fluence. This result and our previous XPS result show that the ion-irradiation produced oxygen vacancies. The present study implies that the ferromagnetic behavior of the ion-irradiated CeO
is attributed to the magnetic moments of localized 4f electrons on Ce
atoms, which are related to oxygen vacancies.
Mitsuda, Tomoaki*; Kobayashi, Ippei*; Kosugi, Shinya*; Fujita, Naoki*; Saito, Yuichi; Hori, Fuminobu*; Semboshi, Satoshi*; Kaneno, Yasuyuki*; Nishida, Kenji*; Soneda, Naoki*; et al.
Nuclear Instruments and Methods in Physics Research B, 272, p.49 - 52, 2012/02
Times Cited Count:10 Percentile:58.60(Instruments & Instrumentation)Ishikawa, Norito; Sonoda, Takeshi*; Okamoto, Yoshihiro; Sawabe, Takashi*; Takegahara, Keisuke; Kosugi, Shinya*; Iwase, Akihiro*
Journal of Nuclear Materials, 419(1-3), p.392 - 396, 2011/12
Times Cited Count:11 Percentile:62.35(Materials Science, Multidisciplinary)In order to characterize the radiation damage due to ion-track formation in UO, polycrystalline samples have been irradiated with 210-MeV Xe ions, and measured with XRD (X-ray diffraction) technique using Cu X-ray. We have also tried EXAFS (extended X-ray absorption fine structure) measurement using X-ray near U L
-edge. The results show that XRD technique detects damage at relatively low fluence of 10
ions/m
and higher, while the irradiation-induced change of EXAFS spectra is not observed even at highest fluence of 10
ions/m
. The damage detection may be critically influenced by the depth profile of X-ray penetration.
Tahara, Yuki*; Zhu, B.-L.*; Kosugi, Shinya*; Ishikawa, Norito; Okamoto, Yoshihiro; Hori, Fuminobu*; Matsui, Toshiyuki*; Iwase, Akihiro*
Nuclear Instruments and Methods in Physics Research B, 269(9), p.886 - 889, 2011/05
Times Cited Count:17 Percentile:74.49(Instruments & Instrumentation)CeO pellets doped with Gd
O
were irradiated with 200-MeV Xe ions, and the effects of Gd
O
-doping and irradiation on the lattice structure were measured using XRD and EXAFS. The lattice constant decreases with increasing Gd
O
-doping and the local structure near the Gd atoms is more disordered with increasing amounts of Gd
O
-dopant. The irradiation induces an expansion of the lattice and disordering of the atomic arrangement around Gd atoms. The effect of high-energy ion irradiation becomes more pronounced with increasing amounts of Gd
O
-dopant.
Kosugi, Shinya*; Fujita, Naoki*; Matsui, Toshiyuki*; Hori, Fuminobu*; Saito, Yuichi; Ishikawa, Norito; Okamoto, Yoshihiro; Iwase, Akihiro*
Nuclear Instruments and Methods in Physics Research B, 269(9), p.869 - 872, 2011/05
Times Cited Count:10 Percentile:59.29(Instruments & Instrumentation)Effects of thermal annealing on ion-irradiation induced ferromagnetism of FeRh bulk alloy and the related structural change were investigated by means of superconducting quantum interference device (SQUID) and extended X-ray absorption fine structure (EXAFS), respectively. Depending on the annealing temperature from 100 to 500 C, the magnetization induced by 10 MeV iodine ion irradiation and the lattice structure of the alloy were remarkably changed. After 500
C annealing, the magnetization and the lattice ordering of the alloy become similar to the states before the irradiation. The experimental result indicates that the thermal relaxation of irradiation-induced atomic disordering dominates the magnetic state of ion-irradiated FeRh alloy.
Kosugi, Shinya*; Matsui, Toshiyuki*; Ishikawa, Norito; Ito, Masayoshi*; Sakurai, Yoshiharu*; Aiko, Kazuma*; Shimizu, Hirotaka*; Tahara, Yuki*; Hori, Fuminobu*; Iwase, Akihiro*
Journal of Applied Physics, 109(7), p.07B737_1 - 07B737_3, 2011/04
Times Cited Count:7 Percentile:30.41(Physics, Applied)The magnetic Compton profiles of FeRh intermetallic compound were measured to study the ferromagnetism induced by 200 MeV Xe ion irradiation. The magnetic effect at 50 K increases with increasing the ion-fluence. The analysis of the experimental result revealed that the values of spin moment induced by the irradiation were close to the values of magnetization obtained by a superconducting quantum interference device magnetometer, suggesting that the ion irradiation mainly induces the spin magnetic moment.
Kosugi, Shinya*; Ishikawa, Norito; Saito, Yuichi; Hori, Fuminobu*; Iwase, Akihiro*
Journal of Nuclear Materials, 411(1-3), p.171 - 173, 2011/04
Times Cited Count:3 Percentile:25.12(Materials Science, Multidisciplinary)Changes in electrical resistivity induced by irradiation with energetic electrons were measured for Fe-50 at.%Rh alloy as a function of electron energy in the range from 0.5 to 2.0 MeV. The irradiation was carried out below 20 K and the resistivity was measured at 10 K. The electron energy dependence of the resistivity change rate was analysed by using a simple displacement theory, and the average threshold energies for atomic displacements, , were determined as 30 eV for Fe and 45 eV for Rh.
Mitsuda, Tomoaki*; Kobayashi, Ippei*; Kosugi, Shinya*; Fujita, Naoki*; Saito, Yuichi; Hori, Fuminobu*; Semboshi, Satoshi*; Kaneno, Yasuyuki*; Nishida, Kenji*; Soneda, Naoki*; et al.
Journal of Nuclear Materials, 408(2), p.201 - 204, 2011/01
Times Cited Count:14 Percentile:70.49(Materials Science, Multidisciplinary)Fujita, Naoki*; Matsui, Toshiyuki*; Kosugi, Shinya*; Sato, Takahiro; Saito, Yuichi; Takano, Katsuyoshi; Koka, Masashi; Kamiya, Tomihiro; Seki, Shu*; Iwase, Akihiro*
Japanese Journal of Applied Physics, 49(6), p.060211_1 - 060211_3, 2010/06
Times Cited Count:12 Percentile:44.94(Physics, Applied)Fujita, Naoki*; Kosugi, Shinya*; Zushi, Yoshihiro*; Matsui, Toshiyuki*; Saito, Yuichi; Iwase, Akihiro*
Nuclear Instruments and Methods in Physics Research B, 267(6), p.921 - 924, 2009/04
Times Cited Count:9 Percentile:52.95(Instruments & Instrumentation)Tahara, Yuki*; Zhu, B.-L.*; Kosugi, Shinya*; Hori, Fuminobu*; Matsui, Toshiyuki*; Iwase, Akihiro*; Ishikawa, Norito; Okamoto, Yoshihiro; Baba, Yuji; Hirao, Norie
no journal, ,
no abstracts in English
Tahara, Yuki*; Zhu, B.-L.*; Kosugi, Shinya*; Hori, Fuminobu*; Matsui, Toshiyuki*; Iwase, Akihiro*; Ishikawa, Norito; Okamoto, Yoshihiro; Baba, Yuji; Hirao, Norie
no journal, ,
no abstracts in English
Tahara, Yuki*; Zhu, B.-L.*; Kosugi, Shinya*; Ishikawa, Norito; Okamoto, Yoshihiro; Baba, Yuji; Hirao, Norie; Hori, Fuminobu*; Matsui, Toshiyuki*; Iwase, Akihiro*
no journal, ,
In present light-water nuclear power plants, it is useful to dope some elements, which have a high neutron absorption cross section, into fuels (UO) in order to control the initial reactivity. During the operation of reactors, UO
fuels are exposed to irradiation with high energy fission products which have energies around 100 MeV. Therefore, it is important to study the effects of high energy fission products on UO
fuels. Cerium dioxide (CeO
) has been used so far as a simulation material for UO
because it has the same fluorite structure as that of UO
. In this study, CeO
pellets doped with Gd
O
were irradiated with 200 MeV Xe
ions to simulate the irradiation effects of high energy fission products on UO
doped with Gd
O
. The X-ray diffraction spectra show that the lattice constant of CeO
increases with increasing the amount of the Gd-doping. In addition, it also increases by the irradiation and the effect of the irradiation becomes more remarkable by doping Gd
O
.