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Your search keyword '"U. Ito, Takashi"' showing total 14 results
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14 results on '"U. Ito, Takashi"'

3. Magnetic Bragg peak enhancement under ultrasound injection

Author

Shin-ichi, Shamoto, Akatsu, Mitsuhiro, Matsuura, Masato, Seiko, Ohira-Kawamura, Kazuya, Harii, Ono, Masao, Lieh-Jeng, Cheng, U. Ito, Takashi, Nemoto, Yuichi, Jun'ichi, Ieda, Shin-ichi, Shamoto, Akatsu, Mitsuhiro, Matsuura, Masato, Seiko, Ohira-Kawamura, Kazuya, Harii, Ono, Masao, Lieh-Jeng, Cheng, U. Ito, Takashi, Nemoto, Yuichi, and Jun'ichi, Ieda

Abstract

Ultrasound injection effect on a magnetic Bragg peak of yttrium iron garnet has been studied by quasielastic neutron scattering. The magnetic Bragg peak is vastly enhanced with decreasing temperature. The energy-width increases proportionally to the square root of the sample temperature increase induced by the ultrasound injection. Because the magnetic Bragg peak is enhanced by the lattice vibration, the enhancement is expected to closely relate to the spin-lattice coupling. An observed sharp drop above 100 K in the longitudinal mode suggests the degradation of the spin-lattice coupling. It is consistent with the decline of spin Seebeck effect with increasing temperature above 100 K, proving the degradation mechanism by the spin-lattice coupling.

Published
2022

11. µSR Studies of Pu Metal and the Pu-based Superconductor PuCoGa5

Author

H. Heffner, Robert, primary, D. Bauer, Eric, additional, Chung, B., additional, J. Fluss, Michael, additional, Higemoto, Wataru, additional, U. Ito, Takashi, additional, E. MacLaughlin, Douglas, additional, A. Morales, Luis, additional, D. Morris, Gerald, additional, Ohishi, Kazuki, additional, L. Sarrao, John, additional, and Shu, Lei, additional

Published
2006
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14. Local electronic structure of interstitial hydrogen in MgH 2 inferred from muon study.

Author

Kadono R, Hiraishi M, Okabe H, Koda A, and U Ito T

Abstract

Magnesium hydride has great potential as a solid hydrogen (H) storage material because of its high H storage capacity of 7.6 wt%. However, its slow hydrogenation and dehydrogenation kinetics and the high temperature of 300  ∘ C required for decomposition are major obstacles to small-scale applications such as automobiles. The local electronic structure of interstitial H in MgH 2 is an important fundamental knowledge in solving this problem, which has been studied mainly based on density functional theory (DFT). However, few experimental studies have been performed to assess the results of DFT calculations. We have therefore introduced muon (Mu) as pseudo-H into MgH 2 and investigated the corresponding interstitial H states by analyzing their electronic and dynamical properties in detail. As a result, we observed multiple Mu states similar to those observed in wide-gap oxides, and found that their electronic states can be attributed to relaxed-excited states associated with donor/acceptor levels predicted by the recently proposed 'ambipolarity model'. This provides an indirect support for the DFT calculations on which the model is based via the donor/acceptor levels. An important implication of the muon results for improved hydrogen kinetics is that dehydrogenation, serving as a reduction for hydrides, stabilises the interstitial H - state., (© 2023 IOP Publishing Ltd.)

Published
2023
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