Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Li, C.*; Fang, W.*; Yu, H. Y.*; Peng, T.*; Yao, Z. T.*; Liu, W. G.*; Zhang, X.*; Xu, P. G.; Yin, F.*
Materials Science & Engineering A, 892, p.146096_1 - 146096_11, 2024/02
Times Cited Count:0 Percentile:0.02(Nanoscience & Nanotechnology)Hirota, Yuki*; Tominaga, Taiki*; Kawabata, Takashi*; Kawakita, Yukinobu; Matsuo, Yasumitsu*
Bioengineering (Internet), 10(5), p.622_1 - 622_17, 2023/05
Times Cited Count:0 Percentile:0.01(Biotechnology & Applied Microbiology)Hashimoto, Shunsuke*; Yamaguchi, Satoshi*; Harada, Masashi*; Nakajima, Kenji; Kikuchi, Tatsuya*; Oishi, Kazuki*
Journal of Colloid and Interface Science, 638, p.475 - 486, 2023/05
Times Cited Count:2 Percentile:60.61(Chemistry, Physical)Recently, it has been reported that anomalous improvement in the thermal conductivity of nanofluid composed of base liquids and dispersed solid nanoparticles, compared to the theoretically predicted value calculated from the particle fraction. Generally, the thermal conductivity values of gases and liquids are dominated by the mean free path of the molecules during translational motion. Herein, we present solid evidence showing the possible contribution of the vibrational behavior of liquid molecules around nanoparticles to increasing these thermal conductivities.
Tamatsukuri, Hiromu; Fukui, Keiga*; Iimura, Soshi*; Honda, Takashi*; Tada, Tomofumi*; Murakami, Yoichi*; Yamaura, Junichi*; Kuramoto, Yoshio*; Sagayama, Hajime*; Yamada, Takeshi*; et al.
Physical Review B, 107(18), p.184114_1 - 184114_8, 2023/05
Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)Fujihara, Masayoshi; Hagihara, Masato; Morita, Katsuhiro*; Murai, Naoki; Koda, Akihiro*; Okabe, Hirotaka*; Mitsuda, Setsuo*
Physical Review B, 107(5), p.054435_1 - 054435_8, 2023/02
Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)The = 1/2 Heisenberg linear chain antiferromagnet is the simplest spin model; nevertheless it serves as a platform for various quantum many-body phenomena. Here, we report the magnetic behavior of a quasi-one-dimensional antiferromagnet KCuPOHO. A long-range commensurate antiferromagnetic order with ordered moment 0.31(1) per spin occurs at = 11.7(1) K. Above , the inelastic neutron excitation is characterized by a two spinon continuum. The intrachain interaction and interchain interaction are estimated to be 172 K and 4.25(4) K, respectively; thus the ratio of the / = 0.0247(3). At lower energies, below , a spin gap is observed in the dispersive excitations. These results are consistent with characteristics observed in weakly interacting = 1/2 Heisenberg chain system.
Nakajima, Kenji; Kikuchi, Tatsuya*; Kawamura, Seiko; Kambara, Wataru*
EPJ Web of Conferences, 272, p.02012_1 - 02012_8, 2022/11
We will present some of attempts on AMATEAS, a cold-neutron chopper spectrometer at a pulsed source, to increase time-windows at a single-measurement condition. One of ways is that, by allowing interveined trajectories on the time-of-flight diagram, the usable width selectable for is can be increased. Based on our experiences, the conditions of pulse repetition rate multiplication based polychromatic measurements on chopper spectrometers at pulsed sources will be discussed. Optimization of wide-band polychromatic measurements and a generalized formulated condition will be proposed. Application of our idea to existing spectrometers and to the criteria design of an optimized chopper spectrometer will be also discussed with suggesting further possibility to improve efficiency by modifying the pulse shaping chopper.
Xu, X.*; Odaira, Takumi*; Xu, S.*; Hirata, Kenji*; Omori, Toshihiro*; Ueki, Kosuke*; Ueda, Kyosuke*; Narushima, Takayuki*; Nagasako, Makoto*; Kainuma, Ryosuke*; et al.
Advanced Materials & Processes, 180(7), p.35 - 37, 2022/10
Hirota, Yuki*; Tominaga, Taiki*; Kawabata, Takashi*; Kawakita, Yukinobu; Matsuo, Yasumitsu*
Bioengineering (Internet), 9(10), p.599_1 - 599_17, 2022/10
Times Cited Count:2 Percentile:32.07(Biotechnology & Applied Microbiology)Hattori, Takanori; Nakamura, Mitsutaka; Iida, Kazuki*; Machida, Akihiko*; Sano, Asami; Machida, Shinichi*; Arima, Hiroshi*; Oshita, Hidetoshi*; Honda, Takashi*; Ikeda, Kazutaka*; et al.
Physical Review B, 106(13), p.134309_1 - 134309_9, 2022/10
Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)Hydrogen vibration excitations of fluorite-type ZrH and TiH were investigated up to 21 GPa and 4 GPa, respectively, by incoherent inelastic neutron scattering experiments. The first excitation energies increased with pressure, as described by the equations (meV) = 141.4(2) + 1.02(2)(GPa) and (meV) = 149.4(1) + 1.21(8)(GPa) for ZrH and TiH, respectively. Coupling with pressure dependence of lattice parameters, the relations between metal-hydrogen distance () and are found to be well described by the equations (meV) = 1.62(9) 10 ((meV) = 1.47(21) 10 (AA), respectively. The slopes of these curves are much steep compared to the previously reported trend in various fluorite-type metal hydrides at ambient pressure. The hydrogen wave function spreading showed that the local potential field for a hydrogen atom shrinks more intensively than the tetrahedral site. These behavior is likely caused by the rigid metal ion core and the resulting confinement of the hydrogen atom in the narrower potential field at high pressures.
Odaira, Takumi*; Xu, S.*; Hirata, Kenji*; Xu, X.*; Omori, Toshihiro*; Ueki, Kosuke*; Ueda, Kyosuke*; Narushima, Takayuki*; Nagasako, Makoto*; Harjo, S.; et al.
Advanced Materials, 34(27), p.2202305_1 - 2202305_11, 2022/07
Times Cited Count:12 Percentile:87.92(Chemistry, Multidisciplinary)Puebla, J.*; Hwang, Y.*; Maekawa, Sadamichi*; Otani, Yoshichika*
Applied Physics Letters, 120(22), p.220502_1 - 220502_9, 2022/05
Times Cited Count:20 Percentile:93.77(Physics, Applied)Metoki, Naoto; Shibata, Kaoru; Matsuura, Masato*; Kitazawa, Hideaki*; Suzuki, Hiroyuki*; Yamauchi, Hiroki; Hagihara, Masato; Frontzek, M. D.*; Matsuda, Masaaki*
Journal of the Physical Society of Japan, 91(5), p.054710_1 - 054710_6, 2022/05
Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)Hyperfine splitting of Nd nuclei in NdPdAl has been studied by means of high-resolution neutron spectroscopy. We observed inelastic peaks at eV coming from the hyperfine splitting in the magnetically ordered phase due to the hyperfine interactions between Nd nuclei (=7/2) and the 4 electrons with ground state composed of mainly . At very low temperatures, nuclear spin of Nd is polarized with increasing occupation probability of low energy levels and contributes to the enhancement of the antiferromagnetic Bragg intensities: the elastic non-spin-flip channel is dominant. As an application of this phenomenon, we determined the Nd moment and hyperfine splitting from the temperature dependence of an antiferromagnetic Bragg intensities for NdPdGe.
Furuike, Yoshihiko*; Ouyang, D.*; Tominaga, Taiki*; Matsuo, Tatsuhito*; Mukaiyama, Atsushi*; Kawakita, Yukinobu; Fujiwara, Satoru*; Akiyama, Shuji*
Communications Physics (Internet), 5(1), p.75_1 - 75_12, 2022/04
Times Cited Count:4 Percentile:65.23(Physics, Multidisciplinary)Yang, J.*; Ren, W.*; Zhao, X.*; Kikuchi, Tatsuya*; Miao, P.*; Nakajima, Kenji; Li, B.*; Zhang, Z.*
Journal of Materials Science & Technology, 99, p.55 - 60, 2022/02
Times Cited Count:6 Percentile:39.91(Materials Science, Multidisciplinary)High-entropy alloys are characteristic of extensive atomic occupational disorder on high-symmetric lattices, differing from traditional alloys. Here, we investigate magnetic and thermal transport properties of the prototype face-centered-cubic high-entropy alloy CrMnFeCoNi by combining physical properties measurements and neutron scattering. Direct-current (dc) and alternating-current (ac) magnetizations measurements indicate a mictomagnetic behavior with coexisting antiferromagnetic and ferromagnetic interactions in the entire temperature region and three anomalies are found at about 80, 50, and 20 K, which are related to the paramagnetic to antiferromagnetic transition, the antiferromagnetic to ferromagnetic transition, and the spin freezing, respectively. The electrical and thermal conductivities are significantly reduced compared to Ni and the temperature dependence of lattice thermal conductivity exhibits a glass-like plateau. Inelastic neutron scattering measurements suggest weak anharmonicity so that the thermal transport is expected to be dominated by the defect scattering.
Funato, Takumi*; Matsuo, Mamoru
Physical Review Letters, 128(7), p.077201_1 - 077201_6, 2022/02
Times Cited Count:3 Percentile:56.47(Physics, Multidisciplinary)Hattori, Takanori; Kawamura, Seiko; Kawasaki, Takuro
High Pressure Research, 42(2), p.226 - 235, 2022/00
Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)We have developed a hybrid piston cylinder cell for quasi-elastic neutron scattering (QENS) experiments up to about 1 GPa. It consists of a fretted cylinder made of the high tensile steel (SNCM439) liner and the Al alloy (NA700) jacket. Performance tests revealed that the cell can withstand a pressure of 0.8 GPa without irreversible damage and has 4.4 times larger neutron transmission at 3.14 meV (5.10 in wavelength) than that of a conventional CuBe monobloc cylinder. Combined with the sample assembly devised for suppressing multiple scattering, high quality QENS spectra of water were obtained up to 0.8 GPa. This study illustrates the efficacy of the hybrid cylinders not only for increasing maximum available pressure but also manipulating the available pressure and the signal intensity, depending on the purpose of the experiments.
Tominaga, Taiki*; Sahara, Masae*; Kawakita, Yukinobu; Nakagawa, Hiroshi; Yamada, Takeshi*
Journal of Applied Crystallography, 54(6), p.1631 - 1640, 2021/12
Times Cited Count:4 Percentile:54.54(Chemistry, Multidisciplinary)Matsuura, Masato*; Fujiwara, Yasuyuki*; Moriwake, Hiroki*; Ohara, Koji*; Kawakita, Yukinobu
Physical Review B, 104(9), p.094305_1 - 094305_7, 2021/09
Times Cited Count:5 Percentile:43.44(Materials Science, Multidisciplinary)Funato, Takumi*; Matsuo, Mamoru
Physical Review B, 104(6), p.L060412_1 - L060412_5, 2021/08
Times Cited Count:3 Percentile:26.56(Materials Science, Multidisciplinary)Hashidate, Ryuta; Kato, Shoichi; Onizawa, Takashi; Wakai, Takashi; Kasahara, Naoto*
Proceedings of ASME 2021 Pressure Vessels and Piping Conference (PVP 2021) (Internet), 9 Pages, 2021/07
It is very essential to clarify the structure failure mechanisms under excessive seismic loads. However, structural tests using actual structural materials are very difficult and expensive. Therefore, we have proposed the structure test approach using lead alloys in order to simulate the structure failure mechanisms under the excessive seismic loads. In this study, we conducted material tests using lead alloy and verified the effectiveness of the simulated material tests. Moreover, we formulated inelastic constitutive equations (best fit fatigue curve equation and cyclic stress range - strain range relationship equation) of lead alloy based on the results of a series of material tests. Nonlinear numerical analyses, e.g. finite element analyses, can be performed using the proposed equations. A series of simulation material test technique enables structural tests and analyses using lead alloy to simulate the structure failure phenomena under excessive seismic loads.