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Okita, Shoichiro; Abe, Yutaka*; Tasaki, Seiji*; Fukaya, Yuji
Radioisotopes, 73(3), p.233 - 240, 2024/11
Shamoto, Shinichi; Akatsu, Mitsuhiro*; Chang, L.-J.*; Nemoto, Yuichi*; Ieda, Junichi
Applied Physics Letters, 124(11), p.112402_1 - 112402_5, 2024/03
Times Cited Count:1 Percentile:53.26(Physics, Applied)The magnon excitation by ultrasound injection in YFe
O
is studied by inelastic neutron scattering. Both longitudinal and transverse ultrasound injections enhanced the inelastic neutron scattering intensity.
Wu, P.*; Murai, Naoki; Li, T.*; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Kofu, Maiko; Nakajima, Kenji; Xia, K.*; Peng, K.*; Zhang, Y.*; et al.
New Journal of Physics (Internet), 25(1), p.013032_1 - 013032_11, 2023/01
Times Cited Count:0 Percentile:0.00(Physics, Multidisciplinary)Teshigawara, Makoto; Tsuchikawa, Yusuke*; Ichikawa, Go*; Takata, Shinichi; Mishima, Kenji*; Harada, Masahide; Oi, Motoki; Kawamura, Yukihiko*; Kai, Tetsuya; Kawamura, Seiko; et al.
Nuclear Instruments and Methods in Physics Research A, 929, p.113 - 120, 2019/06
Times Cited Count:21 Percentile:88.97(Instruments & Instrumentation)A nano-diamond is an attractive neutron reflection material below cold neutron energy. The total neutron cross section of a nano-diamond was derived from a neutron transmission measurement over the neutron energy range of 0.2 meV to 100 meV because total neutron cross section data were not available. The total cross section of a nano-diamond with particle size of approximately 5 nm increased with a decrease in neutron energy to 0.2 meV. It was approximately two orders of magnitude larger than that of graphite at 0.2 meV. The contribution of inelastic scattering to the total cross section was to be shown negligible small at neutron energies of 1.2, 1.5, 1.9, 2.6, and 5.9 meV in the inelastic neutron scattering measurement. Moreover, small-angle neutron scattering measurements of the nano-diamond showed a large scattering cross section in the forward direction for low neutron energies.
Metoki, Naoto; Haga, Yoshinori; Yamamoto, Etsuji; Matsuda, Masaaki*
Journal of the Physical Society of Japan, 87(11), p.114712_1 - 114712_9, 2018/11
Times Cited Count:3 Percentile:26.94(Physics, Multidisciplinary)The localized 5 states with 5
(
) configuration of U
ion have been revealed in UPd
Al
. We found that the low-lying states are the same as PrPd
Al
flat orbitals with large
are stabilized by a two-dimensional CEF potential in the unique crystal structure. The present study involves the valence crossover from tetravalent to trivalent in a series of AnPd
Al
, demonstrated by lattice and/or transport anomaly as well as many body effects in the vicinity of the boundary. The valence instability plays important role for the unusual heavy fermion superconductivity in NpPd
Al
.
Metoki, Naoto; Yamauchi, Hiroki; Suzuki, Hiroyuki*; Kitazawa, Hideaki*; Hagihara, Masato*; Masuda, Takatsugu*; Aczel, A. A.*; Chi, S.*; Hong, T.*; Matsuda, Masaaki*; et al.
Journal of the Physical Society of Japan, 87(9), p.094704_1 - 094704_8, 2018/09
Times Cited Count:6 Percentile:43.38(Physics, Multidisciplinary)The -electron states of PrPd
Al
were revealed by neutron inelastic scattering. The flat
-orbitals with large
become stable under the two-dimensional CEF potential of unique crystal structure, which is the origin of the Ising anisotropy. A systematic understanding is possible in RPd
Al
based on this CEF potential. Especially the
-type anisotropy in NpPd
Al
can be qualitatively understood with the positive Stevens factors. It mean that the local property is important for the physical properties of RPd
Al
including the heavy fermion superconductivity in NpPd
Al
.
Metoki, Naoto; Yamauchi, Hiroki; Suzuki, Hiroyuki*; Kitazawa, Hideaki*; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro
Journal of the Physical Society of Japan, 87(8), p.084708_1 - 084708_7, 2018/08
Times Cited Count:6 Percentile:43.38(Physics, Multidisciplinary)Inelastic neutron scattering experiments were carried out in order to study the -electron states of NdPd
Al
The CEF levels at 0K, 35.4K, 88.3K, 101.5K, and 198.8K were clarified from the excitation spectra. The
ground state contains the orbital with
as a main component due to a large negative B
K, which is the origin of the strong uniaxial anisotropy. The estimated magnetic moment, the calculated susceptibility, magnetization curve, and specific heat are in good agreement with the experimental data. The existence of a common charge distribution with CePd
Al
and PrPd
Al
. Indicates that a localized character is important even in actinide-based iso-structural compounds as actually observed in UPd
Al
and also NpPd
Al
, in which the valence crossover plays important role for the heavy fermion superconductivity.
Tsutsui, Satoshi*; Kaneko, Koji; Pospisil, J.; Haga, Yoshinori
Physica B; Condensed Matter, 536, p.24 - 27, 2018/05
Times Cited Count:3 Percentile:13.76(Physics, Condensed Matter)Inoue, Rintaro*; Kanaya, Toshiji*; Yamada, Takeshi*; Shibata, Kaoru; Fukao, Koji*
Physical Review E, 97(1), p.012501_1 - 012501_6, 2018/01
Times Cited Count:10 Percentile:61.47(Physics, Fluids & Plasmas)In this study, we investigate the process of a polystyrene thin film using inelastic neutron scattering (INS), dielectric relaxation spectroscopy (DRS), and thermal expansion spectroscopy (TES). The DRS and TES measurements exhibited a decrease in glass transition temperature (
) with film thickness. On the other hand, an increase in
was observed in INS studies. In order to interpret this contradiction, we investigated the temperature dependence of the peak frequency (
) of the
process probed by DRS and TES. The experiments revealed an increase in the peak frequency (
) with decreasing film thickness in the frequency region. This observation is consistent with the observed decrease in
with thickness. The discrepancy between INS and DRS or TES descriptions of the
process is likely to be attributed to a decrease in the apparent activation energy with film thickness and reduced mobility, due to the impenetrable wall effect.
Li, B.; Kawakita, Yukinobu; Liu, Y.*; Wang, M.*; Matsuura, Masato*; Shibata, Kaoru; Kawamura, Seiko; Yamada, Takeshi*; Lin, S.*; Nakajima, Kenji; et al.
Nature Communications (Internet), 8, p.16086_1 - 16086_9, 2017/06
Times Cited Count:84 Percentile:90.11(Multidisciplinary Sciences)Hosokawa, Shinya*; Kimura, Koji*; Yamasaki, Michiaki*; Kawamura, Yoshihito*; Yoshida, Koji*; Inui, Masanori*; Tsutsui, Satoshi*; Baron, A. Q. R.*; Kawakita, Yukinobu; Ito, Shinichi*
Journal of Alloys and Compounds, 695, p.426 - 432, 2017/02
Times Cited Count:5 Percentile:23.33(Chemistry, Physical)Kuwahara, Keitaro*; Iwasa, Kazuaki*; Kogi, Masafumi*; Kaneko, Koji; Metoki, Naoto; Raymond, S.*; Masson, M.-A.*; Flouquet, J.*; Sugawara, Hitoshi*; Aoki, Yuji*; et al.
Physica B; Condensed Matter, 385-386(Part 1), p.82 - 84, 2006/11
Times Cited Count:3 Percentile:17.20(Physics, Condensed Matter)We report inelastic neutron scattering experiments performed to investigate the low energy magnetic excitations on single crystals of the heavy-fermion superconductor PrOsSb
. The observed excitation clearly softens at a wave vector Q=(1,0,0), which is the same as the modulation vector of the field-induced antiferro-quadrupolar ordering, and its intensity at Q=(1,0,0) is smaller than that around the zone center. This result directly evidences that this excitonic behavior is derived mainly from nonmagnetic quadrupolar interactions. Furthermore, the narrowing of the linewidths of the excitations below the superconducting transition temperature indicates the close connection between the superconductivity and the excitons.
Ishii, Kenji; Tsutsui, Kenji*; Endo, Yasuo*; Toyama, Takami*; Kuzushita, Kaori; Inami, Toshiya; Owada, Kenji; Maekawa, Sadamichi*; Masui, Takahiko*; Tajima, Setsuko*; et al.
AIP Conference Proceedings 850, p.445 - 446, 2006/09
Mott gap excitations in the optimally doped high- superconductor YBa
Cu
O
(
= 93 K) have been studied by the resonant inelastic X-ray scattering method. Anisotropic spectra in the
-plane are observed in a twin-free crystal. The excitation from the one-dimensional CuO chain is enhanced at 2 eV near the zone boundary of the
direction, while the excitation from the CuO
plane is broad at 1.5-4 eV and almost independent of the momentum transfer. Theoretical calculation based on the one-dimensional and two-dimensional Hubbard model reproduces the observed spectra when different values of the on-site Coulomb energy are assumed. The Mott gap of the CuO chain site is found to be much smaller than that of the CuO
plane site.
Ishii, Kenji; Tsutsui, Kenji*; Endo, Yasuo*; Toyama, Takami*; Maekawa, Sadamichi*; Hoesch, M.; Kuzushita, Kaori; Inami, Toshiya; Tsubota, Masami; Yamada, Kazuyoshi*; et al.
AIP Conference Proceedings 850, p.403 - 404, 2006/09
We report a resonant inelastic X-ray scattering (RIXS) study of charge excitations in the electron-doped high- superconductor Nd
Ce
CuO
. The intraband and interband excitations across the Fermi energy are separated for the first time by tuning the experimental conditions properly to measure charge excitations at low energy. A dispersion relation with
-dependent width emerges clearly in the intraband excitation, while the intensity of the interband excitation is concentrated around 2 eV near the zone center. The experimental results are consistent with theoretical calculation of the RIXS spectra based on the Hubbard model.
Ishii, Kenji; Inami, Toshiya; Owada, Kenji; Kuzushita, Kaori; Mizuki, Junichiro; Murakami, Yoichi; Ishihara, Sumio*; Endo, Yasuo*; Maekawa, Sadamichi*; Hirota, Kazuma*; et al.
Journal of Physics and Chemistry of Solids, 66(12), p.2157 - 2162, 2005/12
Times Cited Count:0 Percentile:0.00(Chemistry, Multidisciplinary)We have studied electronic excitations of hole-doped manganese oxides LaSr
MnO
(
and
) by resonant inelastic X-ray scattering at Mn K absorption edge. We observed in the excitation spectra that the Mott gap of La
Sr
MnO
was filled by hole-doping. In La
Sr
MnO
, which shows a metal-insulator transition, we found that temperature dependence of scattering intensity is different between two scattering vectors. It may reflects a anisotropic electronic structure which originates from the orbital degrees of freedom in manganese oxides.
Kuwahara, Keitaro*; Iwasa, Kazuaki*; Kogi, Masafumi*; Kaneko, Koji; Metoki, Naoto; Raymond, S.*; Masson, M.-A.*; Flouquet, J.*; Sugawara, Hitoshi*; Aoki, Yuji*; et al.
Physical Review Letters, 95(10), p.107003_1 - 107003_4, 2005/09
Times Cited Count:96 Percentile:91.76(Physics, Multidisciplinary)We report inelastic neutron scattering experiments performed to investigate the low energy magnetic excitations on single crystals of the heavy-fermion superconductor PrOsSb
. The observed excitation clearly softens at a wave vector
= (1,0,0), which is the same as the modulation vector of the field-induced antiferro-quadrupolar ordering, and its intensity at
= (1,0,0) is smaller than that around the zone center. This result directly evidences that this excitonic behavior is derived mainly from nonmagnetic quadrupolar interactions. Furthermore, the narrowing of the linewidths of the excitations below the superconducting transition temperature indicates the close connection between the superconductivity and the excitons.
Ichihara, Akira; Kunieda, Satoshi; Chiba, Satoshi; Iwamoto, Osamu; Shibata, Keiichi; Nakagawa, Tsuneo; Fukahori, Tokio; Katakura, Junichi
JAERI-Data/Code 2005-004, 54 Pages, 2005/07
The computer code, POD, was developed to calculate angle-differential cross sections and analyzing powers for shape-elastic scattering for collisions of neutron or light ions with target nucleus. The cross sections are computed with the optical model. Angle-differential cross sections for neutron inelastic scattering can also be calculated with the distorted-wave Born approximation. The optical model potential parameters are the most essential inputs for those model computations. The cross sections and analyzing powers are obtained by using the existing local or global parameters. The parameters can also be inputted by users. In this report, the theoretical formulas, the computational methods, and the input parameters are explained. The sample inputs and outputs are also presented.
Raymond, S.*; Flouquet, J.*; Kuwahara, Keitaro*; Iwasa, Kazuaki*; Kogi, Masafumi*; Kaneko, Koji; Metoki, Naoto; Sugawara, Hitoshi*; Aoki, Yuji*; Sato, Hideyuki*
Physica B; Condensed Matter, 359-361, p.898 - 900, 2005/06
Times Cited Count:2 Percentile:11.14(Physics, Condensed Matter)The low lying magnetic excitations of the unconventional heavy fermion superconductor PrOsSb
were studied by inelastic neutron scattering on single crystalline sample. The crystal field excitation first evidenced at 0.7 meV on powder samples is found to have a minimum of energy at the zone boundary corresponding to the wavevector of antiferro-quadrupolar instability. The evolution of the magnetic excitation spectrum under magnetic field confirms the singlet ground state.
Yamauchi, Hiroki; Igawa, Naoki; Ishii, Yoshinobu
Proceedings of 5th International Conference on Gas Hydrates (ICGH-5), Volume 5, p.1615 - 1618, 2005/06
Inelastic neutron scattering experiments were carried out on powdered methane hydrate. In order to observe the precise spectra inelastic neutron scattering without the influence of incoherent contribution, the fully deuterated sample was used for the measurements. The relatively clear excitation peaks were observed at about 6.5 meV and 10 meV mainly corresponding to the transverse acoustic modes and exhibited only very little temperature dependence at 10 K and 100 K. On the other hand, the small shoulder found around 4 meV at 10 K showed apparent temperature dependence. The scattering intensity of this shoulder appeared to broaden and decrease at 100 K, which can be attributed to the increasing anharmonic contribution to the translational motion of the methane molecules encaged in the large cages.
Ishii, Kenji; Tsutsui, Kenji*; Endo, Yasuo*; Toyama, Takami*; Kuzushita, Kaori; Inami, Toshiya; Owada, Kenji; Maekawa, Sadamichi*; Masui, Takahiko*; Tajima, Setsuko*; et al.
Physical Review Letters, 94(18), p.187002_1 - 187002_4, 2005/05
Times Cited Count:40 Percentile:80.37(Physics, Multidisciplinary)Mott gap excitations in the optimally doped high- superconductor YBa
Cu
O
(
= 93 K) have been studied by the resonant inelastic X-ray scattering method. Anisotropic spectra in the
-plane are observed in a twin-free crystal. The excitation from the one-dimensional CuO chain is enhanced at 2 eV near the zone boundary of the
direction, while the excitation from the CuO
plane is broad at 1.5-4 eV and almost independent of the momentum transfer. Theoretical calculation based on the one-dimensional and two-dimensional Hubbard model reproduces the observed spectra when different values of the on-site Coulomb energy are assumed. The Mott gap of the CuO chain site is found to be much smaller than that of the CuO
plane site.