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Mori, Yuichiro*; Kagi, Hiroyuki*; Aoki, Katsutoshi*; Takano, Masahiro*; Kakizawa, Sho*; Sano, Asami; Funakoshi, Kenichi*
Earth and Planetary Science Letters, 634, p.118673_1 - 118673_8, 2024/05
To investigate silicon effects on the hydrogen-induced volume expansion of iron, neutron diffraction and X-ray diffraction experiments were conducted to examine hcp-Fe
Si
under high pressures and high temperatures. Neutron diffraction experiments were performed on the deuterated hcp-FeSi at 13.5 GPa and 900 K, and at 12.1 GPa and 300 K. By combining the P-V-T equation of state of hcp-FeSi, present results indicate that the hydrogen-induced volume expansion of hcp-FeSi is 10% greater than that of pure hcp iron. Using the obtained values, we estimated the hydrogen content that would reproduce the density deficit in the inner core, which was 50% less than that without the effect of silicon. Possible hydrogen content, 
, in the inner core and the outer core was calculated to be 0.07 and 0.12-0.15, respectively, when reproducing the density deficit of the inner core with hcp-FeSiHx.
Hattori, Takanori; Sano, Asami; Machida, Shinichi*; Ouchi, Keiichi*; Kira, Hiroshi*; Abe, Jun*; Funakoshi, Kenichi*
High Pressure Research, 40(3), p.325 - 338, 2020/09
Times Cited Count：4 Percentile：38.78(Physics, Multidisciplinary)To understand the practical effects of pressure-transmitting media (PTM) on neutron diffraction using Paris-Edinburgh presses, diffraction patterns of MgO were collected to approximately 20 GPa using PTMs of Pb, AgCl, 4:1 methano-ethanol (ME) mixture with and without heating, N
, and Ar. Hydrostaticity in the sample chamber estimated from the MgO 220 peak width improves in the order of Pb, AgCl, Ar, ME mixture, N, and the heated ME mixture. Unlike previous results using a diamond anvil cell, the unheated ME mixture is superior to Ar even after freezing, probably due to the cup on the anvil face. Considering these results and the sizable coherent scattering of Ne, which would show good hydrostaticity, we conclude that the ME mixture (preferably the heated one) is the best PTM in neutron experiments up to 20 GPa, while Ar can be substituted when a sample is reactive to alcohols.
and Fe
distribution in chevkinite-subgroup minerals; X-ray diffraction, neutron diffraction, 
Fe M
ssbauer spectroscopy and electron-microprobe analysesNagashima, Mariko*; Armbruster, T.*; Akasaka, Masahide*; Sano, Asami; Nishio-Hamane, Daisuke*; Malsy, A.*; Imaoka, Teruyoshi*; Nakashima, Kazuo*
Physics and Chemistry of Minerals, 47(6), p.29_1 - 29_18, 2020/06
Times Cited Count：3 Percentile：17.15(Materials Science, Multidisciplinary)Three non-metamict chevkinite-subgroup minerals, from Cape Ashizuri, Japan, Tangir Valley, Diamar District, Pakistan and Haramosh Mts., Skardu district, Pakistan, were studied by crystal chemical techniques. Powder X-ray diffraction and transmission electron microscopic observations confirmed well crystalline samples. Electron-microprobe analyses indicated the general composition known for chevkinite-(Ce). Site scattering values determined by single-crystal X-ray structure refinements suggested assignment of subordinate Nb to the octahedral M3 and M4 sites, minor Th to M1 for the Ashizuri sample and minor Mg to M1 for both samples from Pakistan. Neutron time-of-flight powder diffraction studies were applied to determine the Ti/Fe distribution among octahedral sites for all samples and Mossbauer spectroscopy served for the Fe valence assignment at the four octahedral sites. The dominant iron valence at M1 of the Haramosh sample is ferric whereas for samples Nos. 1 and 2 iron is ferrous.
Komatsu, Kazuki*; Noritake, Fumiya*; Machida, Shinichi*; Sano, Asami; Hattori, Takanori; Yamane, Ryo*; Kagi, Hiroyuki*
Scientific Reports (Internet), 6, p.28920_1 - 28920_11, 2016/07
Times Cited Count：23 Percentile：54.81(Multidisciplinary Sciences)We investigate in-situ neutron diffraction measurements and density functional theory calculations to revisit the structure and stability of ice XV. We find that none of the completely ordered configurations are particular favored; instead, partially ordered states are established as a mixture of ordered domains in disordered ice VI. This scenario in which several kinds of ordered configuration coexist dispels the contradictions in previous studies. It means that the order disorder pairs in ice polymorphs are not one-to-one correspondent pairs but rather have one-to-n correspondence, where there are possible configurations at finite temperature.
Fe(CN)
accompanied with enhanced conductivityLi, K.*; Zheng, H.*; Hattori, Takanori; Sano, Asami; Tulk, C. A.*; Molaison, J.*; Feygenson, M.*; Ivanov, I. N.*; Yang, W.*; Mao, H.-K.*
Inorganic Chemistry, 54(23), p.11276 - 11282, 2015/12
Times Cited Count：5 Percentile：25.81(Chemistry, Inorganic & Nuclear)Pressure-induced polymerization of triple bonds would produce conductive conjugated double bonds. To find a metal cyanide with a low polymerization pressure, anhydrous LiFe(CN) is synthesized and its crystal structure is determined. The irreversible bonding between the CN
can be realized by use of the industrial apparatus. The conductivity is enhanced by more than 3 orders of magnitude, which makes the polymerized LiFe(CN) a potential cathode material for rechargeable lithium batteries.
Honda, Fuminori; Metoki, Naoto; Kaneko, Koji; Jonen, Shintaro; Yamamoto, Etsuji; Aoki, Dai*; Shiokawa, Yoshinobu*; Shiokawa, Yoshinobu; Onuki, Yoshichika
Physica B; Condensed Matter, 378-380, p.1009 - 1010, 2006/05
Times Cited Count：6 Percentile：31.23(Physics, Condensed Matter)no abstracts in English
antiferromagnet UCrSiMatsuda, Tatsuma; Metoki, Naoto; Haga, Yoshinori; Ikeda, Shugo; Kaneko, Koji; Yamamoto, Etsuji; Onuki, Yoshichika
Journal of Physics; Condensed Matter, 15(28), p.S2023 - S2027, 2003/07
Times Cited Count：4 Percentile：26.93(Physics, Condensed Matter)no abstracts in English
-AlOOH and investigation of symmetrization of hydrogen bondSano, Asami; Hattori, Takanori
no journal, ,
To investigate the relation between the symmetrization of hydrogen bond and change of physical properties in the hydrous mineral of the -AlOOH, we conducted neutron diffraction experiments at the high-pressure neutron diffractometer PLANET in the J-PARC. We observed the disappearance of 021 reflection at high pressure in -AlOOH which indicates the transition from the structure with asymmetric hydrogen bond (
) to that with disordered or symmetric hydrogen bond (
), in agreement with previous single crystal X-ray diffraction study. On the other hand the transition pressure is higher in -AlOOD, which was determined to be 12 GPa. The detail about the hydrogen distribution around the transition pressure and its relevance to the change of compressibility and anomalies in sound velocities will be discussed.
-AlOOHSano, Asami; Hattori, Takanori
no journal, ,
To investigate the relation of change in compression behaviours at high-pressure and hydrogen-bond symmetrization in hydrous mineral -AlOOH, we conducted high-pressure neutron diffraction experiments at the PLANET in the J-PARC. The results indicate the phase transitions occur at 8.4 GPa in -AlOOH and 12.1 GPa in -AlOOD.
Watanabe, Masao; Nojiri, Hiroyuki*; Kihara, Takumi*
no journal, ,
Superconducting DC magnet up to 17 Tesla has developed for neutron scattering experiments. Although the sample environment team in the MLF have several DC superconducting magnets up to 7 Tesla as a sample environment apparatus, some users have requested the preparation of higher field magnets. However, another magnet technology is needed to generate higher than 20 Tesla. However, it is difficult to construct such a large system in the MLF from the point of view of construction space. It is practical to employ a pulsed magnetic field as it enables operation of smaller energy as well as downsizing of the instruments. Therefore, we have been newly developed a compact and transportable pulsed magnet system up to 30 Tesla.
Watanabe, Masao; Nojiri, Hiroyuki*
no journal, ,
In recent years, there has been increasing requirements for experiments under a high magnetic field of several tens of Tesla using neutrons and synchrotron radiation. Superconducting DC magnet up to 17 Tesla has developed for neutron scattering experiments. Although the sample environment team in the MLF have several DC superconducting magnets up to 7 Tesla as a sample environment apparatus, users have requested the preparation of higher field magnets. Therefore, we have been newly developed a compact and transportable pulsed magnet system up to 30 Tesla.
Watanabe, Masao; Nojiri, Hiroyuki*
no journal, ,
In J-PARC MLF, we have been developing a transportable pulsed magnet system for high magnetic field up to 35 T as one of the sample environment equipment so that it can be used in various beamlines. We have newly developed a pulsed magnet system using a GM refrigerator in order to dramatically improve the convenience and practicality for users. And also, we have newly introduced an automatic liquid nitrogen supply equipment. In previous neutron scattering experiments, it was necessary to manually supply liquid nitrogen every a few hours, but with the introduction of the automatic liquid nitrogen supply equipment, it has become possible to operate automatically for several days in maximum. It consists of a vacuum chamber, a GM refrigerator, and a square SUS tube in which a solenoidal coil was inserted. In this presentation, we will report on the characteristics and current status of the pulsed magnet system up to 35 T.
investigated by time-of-flight neutron diffraction in long-pulse magnetic fieldsWatanabe, Masao; Nakajima, Taro*; Inamura, Yasuhiro; Matsui, Kazuki*; Kanda, Tomoki*; Nomoto, Tetsuya*; Oishi, Kazuki*; Kawamura, Yukihiko*; Saito, Hiraku*; Tamatsukuri, Hiromu; et al.
no journal, ,
In recent years, due to advances in precision measurement technology in pulsed magnetic fields, a novel magnetic state was discovered in a strong magnetic field. We constructed a measurement environment that can comprehensively explore the reciprocal lattice space under magnetic fields up to 14 Tesla by combining the long-pulse magnetic field generated by the supercapacitor and pulsed neutrons at J-PARC. This equipment can generate a magnetic field that is sufficiently longer than the time width (about 10 milliseconds) of the multi-wavelength neutron pulse passing through the sample. This method was used to investigate the magnetic phase transition in the frustrated magnet CuFeO.
