Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Shamoto, Shinichi*; Akatsu, Mitsuhiro*; Matsuura, Masato*; Kawamura, Seiko; Harii, Kazuya*; Ono, Masao*; Chang, L.-J.*; Ito, Takashi; Nemoto, Yuichi*; Ieda, Junichi
Physical Review Research (Internet), 4(1), p.013245_1 - 013245_7, 2022/03
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 relate to the spin-lattice coupling closely. 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.
Imai, Masaki; Chudo, Hiroyuki; Ono, Masao; Harii, Kazuya; Matsuo, Mamoru; Onuma, Yuichi*; Maekawa, Sadamichi; Saito, Eiji
Applied Physics Letters, 114(16), p.162402_1 - 162402_4, 2019/04
Times Cited Count:20 Percentile:72.44(Physics, Applied)Imai, Masaki; Ogata, Yudai*; Chudo, Hiroyuki; Ono, Masao; Harii, Kazuya; Matsuo, Mamoru*; Onuma, Yuichi*; Maekawa, Sadamichi; Saito, Eiji
Applied Physics Letters, 113(5), p.052402_1 - 052402_3, 2018/07
Times Cited Count:18 Percentile:65.14(Physics, Applied)Ogata, Yudai; Chudo, Hiroyuki; Gu, B.; Kobayashi, Nobukiyo*; Ono, Masao; Harii, Kazuya; Matsuo, Mamoru; Saito, Eiji; Maekawa, Sadamichi
Journal of Magnetism and Magnetic Materials, 442, p.329 - 331, 2017/11
Times Cited Count:8 Percentile:66.67(Materials Science, Multidisciplinary)Ogata, Yudai; Chudo, Hiroyuki; Ono, Masao; Harii, Kazuya; Matsuo, Mamoru; Maekawa, Sadamichi; Saito, Eiji
Applied Physics Letters, 110(7), p.072409_1 - 072409_4, 2017/02
Times Cited Count:19 Percentile:65.47(Physics, Applied)Takahashi, Ryo*; Matsuo, Mamoru; Ono, Masao; Harii, Kazuya; Chudo, Hiroyuki; Okayasu, Satoru; Ieda, Junichi; Takahashi, Saburo*; Maekawa, Sadamichi; Saito, Eiji
Nature Physics, 12, p.52 - 56, 2016/01
Times Cited Count:109 Percentile:96.35(Physics, Multidisciplinary)Ono, Masao; Chudo, Hiroyuki; Harii, Kazuya; Okayasu, Satoru; Matsuo, Mamoru; Ieda, Junichi; Takahashi, Ryo*; Maekawa, Sadamichi; Saito, Eiji
Physical Review B, 92(17), p.174424_1 - 174424_4, 2015/11
Times Cited Count:30 Percentile:74.42(Materials Science, Multidisciplinary)Harii, Kazuya; Chudo, Hiroyuki; Ono, Masao; Matsuo, Mamoru; Ieda, Junichi; Okayasu, Satoru; Maekawa, Sadamichi; Saito, Eiji
Japanese Journal of Applied Physics, 54(5), p.050302_1 - 050302_3, 2015/05
Times Cited Count:13 Percentile:49.68(Physics, Applied)Chudo, Hiroyuki; Harii, Kazuya; Matsuo, Mamoru; Ieda, Junichi; Ono, Masao; Maekawa, Sadamichi; Saito, Eiji
Journal of the Physical Society of Japan, 84(4), p.043601_1 - 043601_4, 2015/04
Times Cited Count:18 Percentile:72.01(Physics, Multidisciplinary)Ogata, Yudai*; Iguchi, Yusuke*; Tokuda, Makoto*; Januszko, K.*; Khandaker, J. I.*; Ono, Masao; Mashimo, Tsutomu*
Journal of Applied Physics, 117(12), p.125902_1 - 125902_6, 2015/03
Times Cited Count:9 Percentile:34.44(Physics, Applied)Chudo, Hiroyuki; Ono, Masao; Harii, Kazuya; Matsuo, Mamoru; Ieda, Junichi; Haruki, Rie*; Okayasu, Satoru; Maekawa, Sadamichi; Yasuoka, Hiroshi; Saito, Eiji
Applied Physics Express, 7(6), p.063004_1 - 063004_4, 2014/06
Times Cited Count:44 Percentile:84.23(Physics, Applied)A magnetic field is predicted to emerge on a particle in a rotating body even if the body is electrically neutral. This emergent field is called a Barnett field. We show that nuclear magnetic resonance (NMR) enables direct measurement of the Barnett field in solids. We rotated both a sample and an NMR coil synchronously at high speed and found an NMR shift whose sing reflects that of the nuclear magnetic moments. This result provides direct evidence of the Barnett field. The use of NMR for Barnett field measurement enables the unknown signs of nuclear magnetic moments in solids to be determined.
Ono, Masao; Okayasu, Satoru; Iguchi, Yusuke*; Esaka, Fumitaka; Bagum, R.*; Haruki, Rie; Mashimo, Tsutomu*
Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan (Internet), 12(ists29), p.Tq_1 - Tq_3, 2014/04
We had realized the composition gradient of elements or isotopes in some binary alloys or single element by solid-state centrifugation. While, it might difficult to realize graded structure of elements in binary ionic crystal by centrifugation as it strongly keeps their stoichiometry. However, isotope fractionation in binary ionic crystal by centrifugation might be expected as the self-diffusion of ions occurs. We have planed the ultracentrifuge experiments on -AgI superionic conductor to investigate the isotope effect in binary ionic crystal under a strong centrifugal acceleration field. -AgI superionic conductor is suitable for the confirmation experiment as it is an intrinsic ionic crystal and Ag ions have high diffusivity. For the first stage, we have experimentally searched the experimental conditions of magnitude of centrifugal acceleration and temperature that ensure the experiment without decomposition. It is confirmed that the combination of experimental conditions of up to 6.110 g, 350C, 24h ensure the experiment without decomposition at least.
Okayasu, Satoru; Ono, Masao; Nishio, Taichiro*; Iguchi, Yusuke*; Mashimo, Tsutomu*
Defect and Diffusion Forum, 323-325, p.545 - 548, 2012/04
Times Cited Count:0 Percentile:0.01(Nanoscience & Nanotechnology)Atomic sedimentation in solid occurs under mega-gravity treatment. As the result, partially melt-growth in -phase of BiPb-alloy occurs. Small difference of densities between fully hcp structure of BiPb and that of partially defected BiPb are enhanced under mega-gravity, and cause the separation of the -phase. Superconducting properties differs between the separated two phases.
Ono, Masao; Okayasu, Satoru; Esaka, Fumitaka; Haruki, Rie; Mashimo, Tsutomu*
Journal of the Japan Society of Microgravity Application, 28(2), p.S89 - S91, 2011/04
An ultracentrifuge experiment was performed on a pure liquid-indium at acceleration field of 8.210 g at 300C for 100 hours. The isotope ratio measurements were performed on the centrifuged specimen with Secondary Ion Mass Spectrometer (CAMECA IMS-6f). In/In isotope ratio on the specimen changed with negative gradient in the direction of centrifugal force approximately 1.3%. The measurement result indicated that the heavy In isotopes moved in the direction of the centrifugal force and the light In isotopes moved in the counter direction in the specimen. At the session, we will present both the result and an approach to find a precondition to develop an isotope separation process using the phenomenon.
Iguchi, Yusuke*; Mashimo, Tsutomu*; Ono, Masao; Okayasu, Satoru
Philosophical Magazine Letters, 90(7), p.513 - 518, 2010/07
Times Cited Count:4 Percentile:29.14(Materials Science, Multidisciplinary)We performed an ultracentrifuge experiment on Bi-Sb alloy. Deformation twins with misorientations of about 90 were observed in the low-gravitational region where grain refinement had not occurred. The twins were thicker than the conventional deformation twins and their thickness was proportional to the gravitational field. We found that the minimum gravitational field required for grain refinement was 1.710 G at 240 C for periods 10 h.
Hao, T.; Ono, Masao; Okayasu, Satoru; Sakai, Seiji; Narumi, Kazumasa; Hiraiwa, Yusuke*; Naramoto, Hiroshi*; Maeda, Yoshihito
Nuclear Instruments and Methods in Physics Research B, 268(11-12), p.1867 - 1870, 2010/06
Times Cited Count:6 Percentile:39.61(Instruments & Instrumentation)Ono, Masao; Sueyoshi, Masanori*; Okayasu, Satoru; Hao, T.; Esaka, Fumitaka; Osawa, Takahito; Iguchi, Yusuke*; Mashimo, Tsutomu
Review of Scientific Instruments, 80(8), p.083908_1 - 083908_6, 2009/08
Times Cited Count:3 Percentile:17.76(Instruments & Instrumentation)A prototype rotor with 2 grooves for the multi-stage centrifugal isotope separation in solid state was developed to test a new idea. This idea is based on the sedimentation of constitutional atoms in solid. In the performance test using indium specimen, it is verified that the developed rotor can receive all injected molten-indium droplets from an automatic raw-material feeding system even at the high rotational speed of 97,000 r.p.m. without the loss of rotational stability, and the received indium specimens can be transferred in/between 2 grooves through the plastic flow under the influence of strong centrifugal force even in the solid state. The isotope ratio of centrifuged indium specimens was analyzed employing the Secondary Ion Mass Spectrometry (SIMS), and it is confirmed that intended isotope separation by the centrifugation is realized in the solid state.
Ono, Masao; Iguchi, Yusuke*; Okayasu, Satoru; Esaka, Fumitaka; Kobayashi, Katsura*; Hao, T.; Bagum, R.*; Osawa, Takahito; Fujii, Kimio; Nakamura, Eizo*; et al.
Defect and Diffusion Forum, 289-292, p.63 - 68, 2009/04
The atomic-scale graded structure of In-Pb alloy was formed by an ultracentrifuge experiment under conditions that a gravitational field of 0.8110 G for 100 hours at 150 C in solid state in our previous study. The isotope ratio measurements were performed on the centrifuged sample with secondary ion mass spectrometer (SIMS). Pb/Pb and Pb/Pb isotope ratio changed with negative gradient in the direction of centrifugal force approximately 1.5% and 0.8%, respectively. And three-isotope diagram of Pb/Pb versus Pb/Pb proved that the isotope fluctuation depends on isotopic mass difference. These results showed that the strong gravitational field not only affected on the inter-diffusion but also on self-diffusion in this alloy as causing isotope fractionation effect, and the isotope fractionation was dependent on mass-difference.
Iguchi, Yusuke*; Ono, Masao; Okayasu, Satoru; Mashimo, Tsutomu
Defect and Diffusion Forum, 289-292, p.319 - 322, 2009/04
An atomic-scale graded structure has been formed by sedimentation of substitutional atoms under an ultra-strong gravitational field of 1 million G level in alloys and compounds. In this study, we investigate the sedimentation of impurity atoms in semiconductor materials under a strong gravitational field. High-temperature ultracentrifuge experiments (0.5910 G, 400C, 60 hours) have been performed on an InSb single crystal wafer which surface was coated with Ge by means of Physical Vapor Deposition (PVD). It was observed that the penetration depth of diffused Ge atoms under the gravitational field was several times larger than under terrestrial field at the same temperatures.
Mashimo, Tsutomu; Iguchi, Yusuke*; Bagum, R.*; Sano, Tomokazu*; Takeda, Shingo*; Kimura, Shigeru*; Sakata, Osami*; Ono, Masao; Okayasu, Satoru; Tsurui, Takao*; et al.
Defect and Diffusion Forum, 289-292, p.357 - 360, 2009/04
A visible four-layers structure with anomalous nano-sturucture was formed from a homogeneous e-phase BiPb intermetallic compound under a strong gravitational field (1.0210 G, 130C, 100 hours). In the 4th layer (lowest-gravity region), pure Bi particles precipitate. In the 2nd 3rd layers, composition graded structures, where Pb content increased along the gravity direction, were formed. It was found that the very broad XRD peak appeared in the 2nd layer, which indicated that an amorphous structure was contained.