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Journal Articles

The Existence of memory effect on hydrogen ordering in ice; The Effect makes ice attractive

Arakawa, Masashi*; Kagi, Hiroyuki; Fernandez-Baca, J. A.*; Chakoumakos, B.*; Fukazawa, Hiroshi

Geophysical Research Letters, 38, p.L16101_1 - L16101_5, 2011/08

 Times Cited Count:11 Percentile:36.14(Geosciences, Multidisciplinary)

The existence of ferroelectric ice XI with ordered hydrogen in space becomes of interest in astronomy and physical chemistry because of the strong electrostatic force. However, the influence was believed to be limited because it forms at narrow temperature range. From neutron diffraction experiments, we found that small hydrogen-ordered domains exist at significantly higher temperature and the domains induce the growth of "bulk" ice XI. The small ordered domain is named "memory" of hydrogen ordered ice because it is the residual structure of ice XI. Since the memory exists up to at least 111 K, most of ices in the solar system are hydrogen ordered and may have ferroelectricity. The small hydrogen-ordered domains govern the cosmochemical properties of ice and evolution of icy grains in the universe.

Journal Articles

Structure and properties of ferroelectric ice

Fukazawa, Hiroshi; Arakawa, Masashi*; Kagi, Hiroyuki; Yamauchi, Hiroki; Chakoumakos, B. C.*; Fernandez-Baca, J. A.*

Physics and Chemistry of Ice 2010, p.421 - 428, 2011/03

Whether or not ice in the universe exists as ferroelectric is a question that has attracted interest in astrophysics and physical chemistry, because long-range electrostatic forces, caused by the ferroelectricity, might be an important factor for materials evolution and hydrogen bonding. From neutron diffraction and scattering measurements, we have studied ice with impurities, such as potassium, sodium and lithium, that acted as a catalyst. Time-resolved diffraction experiments show that ferroelectric ice XI with hydrogen-ordered arrangement nucleates and grows with time for about 5 days. We found that the doped ice that has once been converted to ice XI is a stronger ferroelectric ice than that has never been converted. We also show the existence of the ferroelectric ice under high-pressure and its formation from compressed amorphous ice.

Journal Articles

Neutron diffraction study of hydrogen-ordered ice XI; Annealing effect and memory effect

Arakawa, Masashi*; Kagi, Hiroyuki; Fernandez-Baca, J. A.*; Chakoumakos, B. C.*; Fukazawa, Hiroshi

Physics and Chemistry of Ice 2010, p.329 - 338, 2011/03

We measured neutron diffraction profiles of KOD, NaOD, LiOD, Ca(OD)$$_{2}$$, and ND$$_{3}$$-doped ices. Ice XI, which is a hydrogen-ordered phase of normal ice (ice Ih), was observed in the KOD and NaOD-doped ices although Ca(OD)$$_{2}$$ and ND$$_{3}$$-doped ice did not transformed to ice XI. The mass fraction of ice XI to that of the doped ice ($$f$$) was estimated using Rietveld analysis for each doped ice. The $$f$$ value of the doped ice, which had once experienced being ice XI, was larger than that of the doped ice, which had never experienced being ice XI. The large $$f$$ value of the doped ice indicates that small hydrogen-ordered domains remained above the transition temperature between ice XI and Ih. Our results suggest that large amounts of ice on icy bodies in our solar system can transform to ice XI. In this paper, we discussed the existence of the small hydrogen-ordered domains in space and the evolution of icy grain.

Journal Articles

Annealing effects on hydrogen ordering in KOD-doped ice observed using neutron diffraction

Arakawa, Masashi*; Kagi, Hiroyuki; Fukazawa, Hiroshi

Journal of Molecular Structure, 972(1-3), p.111 - 114, 2010/05

 Times Cited Count:7 Percentile:18.17(Chemistry, Physical)

We measured the neutron powder diffraction of 0.013 M KOD-doped D$$_{2}$$O ice to investigate the formation process of ice XI, a hydrogen-ordered phase of ice Ih. The doped ice Ih transformed to ice XI after annealing at 57 and subsequently at 68 K. The mass fraction of ice XI to that of the doped ice ($$f$$) was estimated using Rietveld analysis for each sample. The $$f$$ value of the doped ice, which had once experienced being ice XI ($$f$$ = 0.23), was larger than that of the doped ice, which had never experienced being ice XI ($$f$$ = 0.14). Results indicate that small hydrogen-ordered domains remained in the ice Ih, which had once trans- formed to ice XI, and accelerated the phase transition from ice Ih to ice XI. Results further suggest that large amounts of ice on icy bodies in our solar system can transform to ice XI, which might be detectable using infrared telescopes or planetary exploration in the near future.

Journal Articles

Performance of the main ring BPM during the beam commissioning at J-PARC

Toyama, Takeshi*; Arakawa, Dai*; Hiramatsu, Shigenori*; Igarashi, Susumu*; Lee, S.*; Matsumoto, Hiroshi*; Odagiri, Junichi*; Tejima, Masaki*; Tobiyama, Makoto*; Hashimoto, Yoshinori*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.981 - 983, 2010/05

Experiences of operating BPM's during beam commissioning at the J-PARC MR are reported. The subjects are: (1) bug report, statistics and especially the effect of a beam duct step, (2) position resolution estimation ($$<$$30 micrometers with 1 sec averaging), (3) beam based alignment.

Journal Articles

A Cubic-anvil high-pressure device for pulsed neutron powder diffraction

Abe, Jun; Arakawa, Masashi*; Hattori, Takanori; Arima, Hiroshi; Kagi, Hiroyuki; Komatsu, Kazuki*; Sano, Asami; Uwatoko, Yoshiya*; Matsubayashi, Kazuyuki*; Harjo, S.; et al.

Review of Scientific Instruments, 81(4), p.043910_1 - 043910_5, 2010/04

 Times Cited Count:6 Percentile:33.58(Instruments & Instrumentation)

A compact cubic-anvil high-pressure device was developed for in situ neutron powder diffraction studies. In this device, a cubic shaped pressure medium is compressed by six anvils, and neutron beam pass through gaps between the anvils. The first high-pressure experiment using this device was conducted at J-PARC and clearly showed the neutron diffraction patterns of Pb. Combining the cubic-anvil high-pressure device with a pulsed neutron source will prove to be a useful tool for neutron diffraction experiments.

Journal Articles

High pressure experiments with the engineering materials diffractometer (BL-19) at J-PARC

Abe, Jun; Hattori, Takanori; Komatsu, Kazuki*; Arima, Hiroshi; Arakawa, Masashi*; Sano, Asami; Kagi, Hiroyuki; Harjo, S.; Ito, Takayoshi; Moriai, Atsushi; et al.

Journal of Physics; Conference Series, 215, p.012023_1 - 012023_6, 2010/03

 Times Cited Count:4 Percentile:83.59

A high-intensity proton accelerator facility named J-PARC has been constructed, and the first neutron beam at J-PARC/MLF was extracted in May of 2008, and user-operation commenced in December of the year. The fist feasibility test of high-pressure neutron experiments were performed with the engineering materials diffractometer "TAKUMI". As results, diffraction profiles of sample embedded in high-pressure devices were obtained. Therefore, it was confirmed that in situ high-pressure neutron diffraction was feasible with the engineering materials diffractometer "TAKUMI".

Journal Articles

Laboratory measurements of infrared absorption spectra of hydrogen-ordered ice; A Step to the exploration of ice XI in space

Arakawa, Masashi; Kagi, Hiroyuki; Fukazawa, Hiroshi

Astrophysical Journal; Supplement Series, 184(1), p.361 - 365, 2009/09

 Times Cited Count:18 Percentile:48.08(Astronomy & Astrophysics)

Infrared absorption spectra of ice were obtained at 4, 60, 100, 140, 160, and 240 K to make spectroscopic observations of hydrogen ordering at low temperatures. A broad peak observed at around 850 cm$$^{-1}$$ (11.7-181 $$mu$$m) was derived from libration of water molecules. The peak width was notably narrower at temperatures less than 140 K. A decrease in the peak width occurring in accordance with the formation of ice with ordered arrangements of hydrogen atoms was suggested from incoherent inelastic neutron-scattering studies. These results are consistent with ordering of hydrogen atoms. Existence of hydrogen-ordered ice in space is the subject of continuing astronomical debate. Our results demonstrate that the ordered ice in space is detectable using infrared telescopes and planetary exploration.

Oral presentation

Space glaciology; Study suggests ferroelectric ice in the Universe

Fukazawa, Hiroshi; Arakawa, Masashi

no journal, , 

We do experiments on ice prepared at much higher pressure conditions. We aim to observe the ferroelectric ice and hydrogen-ordered structures below 130 K using the WAND. We try to observe the phase transition from disordered phases to the ferroelectric ice or other ordered phases around 40$$sim$$130 K (The value is the same as the temperature of Pluto's surface and inner). The experiment will reveal the whole picture of low-temperature ice structures. In this symposium we report recent results at the HFIR and our future plan using higher intensity neutron beam.

Oral presentation

User operation at J-PARC and strategy of high pressure research with neutron

Utsumi, Wataru; Abe, Jun; Hattori, Takanori; Fukazawa, Hiroshi; Yamauchi, Hiroki; Igawa, Naoki; Kagi, Hiroyuki; Arima, Hiroshi*; Arakawa, Masashi; Komatsu, Kazuki*; et al.

no journal, , 

no abstracts in English

Oral presentation

Structure analysis of ferroelectric ice in the Universe based on infrared spectroscopy and neutron diffraction measurements

Kagi, Hiroyuki; Arakawa, Masashi; Fukazawa, Hiroshi

no journal, , 

no abstracts in English

Oral presentation

A High pressure experiment of neutron diffraction at TAKUMI

Abe, Jun; Hattori, Takanori; Arima, Hiroshi; Harjo, S.; Moriai, Atsushi; Ito, Takayoshi; Aizawa, Kazuya; Arai, Masatoshi; Utsumi, Wataru; Arakawa, Masashi; et al.

no journal, , 

The Engineering Materials Diffractometer TAKUMI designed to solve many problems in materials science and engineering including investigations of stresses and crystallographic structures within engineering components was developed at J-PARC. In addition, TAKUMI is suitable for high pressure experiments. High pressure devices (Paris-Edinburgh press and palm cubic anvil press) were developed for in situ neutron powder diffraction experiments under high pressures. In this presentation, we introduce outline of TAKUMI and High pressure devices.

Oral presentation

First results on high-pressure neutron scattering experiments at Takumi in J-PARC

Hattori, Takanori; Abe, Jun; Arima, Hiroshi; Arakawa, Masashi; Komatsu, Kazuki*; Okuchi, Takuo*; Kagi, Hiroyuki; Utsumi, Wataru; Harjo, S.; Ito, Takayoshi

no journal, , 

High-pressure neutron experiments have been limited so far due to the small flux of neutron source. Now, the intense pulse neutron source offered from J-PARC opens up the opportunity. Then, we are trying to do high-pressure neutron experiments, which offers information that have been not obtained so far, such as position of light elements and atomic dynamics. In this talk, we reports first high-pressure TOF results taken at the engineering materials diffractometer TAKUMI in J-PARC, and discuss the future prospect on high-pressure neutron diffraction.

Oral presentation

A Feasibility study of neutron powder diffraction under high pressure with the Engineering Materials Diffractometer "TAKUMI" at J-PARC

Abe, Jun; Hattori, Takanori; Komatsu, Kazuki*; Arima, Hiroshi; Arakawa, Masashi*; Okuchi, Takuo*; Kagi, Hiroyuki; Yagi, Takehiko*; Uwatoko, Yoshiya*; Matsubayashi, Kazuyuki*; et al.

no journal, , 

We have examined the feasibility of in situ neutron powder diffraction under high pressure with the Engineering Materials Diffractometer "TAKUMI", which has been constructed at BL19 in the Materials and Life Science Facility (MLF) of J-PARC. We have tested two types of high pressure devices at TAKUMI, a Paris-Edinburgh press and a Palm cubic anvil cell. Neutron poder diffraction profiles of Pb placed in the high pressure devices as a standard material were collected. As results, diffraction peaks of Pb were clearly observed. In this study, it has been confirmed that in situ neutron powder diffraction under high pressure can be made with a combination of the high pressure devices and the TAKUMI at J-PARC.

Oral presentation

Neutron powder diffraction under high pressure using the engineering materials diffractometer "TAKUMI"

Abe, Jun; Hattori, Takanori; Sano, Asami; Arima, Hiroshi; Fukazawa, Hiroshi; Harjo, S.; Ito, Takayoshi; Aizawa, Kazuya; Utsumi, Wataru; Komatsu, Kazuki*; et al.

no journal, , 

The Engineering Materials Diffractometer TAKUMI designed to solve many problems in materials science and engineering including investigations of stresses and crystallographic structures within engineering components was developed at J-PARC. In addition, TAKUMI is suitable for high-pressure experiments. High-pressure devices (Paris-Edinburgh press, palm cubic anvil press and Diamond Anvil Cell) were developed for in situ neutron powder diffraction experiments under high pressures. However, to apply a these high-pressure devices to neutron diffraction, research and development is needed. Issues to be resolved selecting materials, modifying the diffraction window and reducing BKG.

Oral presentation

High pressure experiments using high-intensity pulsed neutron at "TAKUMI" in J-PARC

Abe, Jun; Arima, Hiroshi; Hattori, Takanori; Komatsu, Kazuki*; Sano, Asami; Arakawa, Masashi*; Okuchi, Takuo*; Kagi, Hiroyuki; Fukazawa, Hiroshi; Utsumi, Wataru

no journal, , 

The Engineering Materials Diffractometer "TAKUMI" has been constructed in the Materials and Life Science Experimental Facility (MLF) of J-PARC. TAKUMI is the neutron powder diffractometer which intended to estimate stress in engineering components. The optical system and the sample stage of TAKUMI are well adapted to high-pressure experiments. In order to confirm the feasibility of high-pressure neutron diffraction at TAKUMI, we have performed a number of R&Ds using a Paris-Edinburgh Press and a Palm cubic anvil cell. As results, diffraction patterns coming from small samples embedded in these high-pressure devices have been obtained. In addition, in situ neutron diffraction of ice at high-pressure and low-temperature conditions ($$sim$$ 1 GPa, $$>$$ 20 K) has been performed. Recently, the further R&Ds have been done; optimization of materials such as anvil and pressure medium, developments of focusing mirror, reduction of background and contamination noise.

Oral presentation

Growth of ferroelectric ice XI doped with alkali metal hydroxide observed using neutron diffraction

Arakawa, Masashi*; Komatsu, Kazuki*; Iizuka, Riko*; Kagi, Hiroyuki; Fernandez-Baca, J. A.*; Chakoumakos, B.*; Yamauchi, Hiroki; Fukazawa, Hiroshi

no journal, , 

We prepared ice XI from different kinds of alkali metal hydroxide solutions with different concentrations, and measured neutron powder diffraction at JRR-3 (Japan Atomic Energy Agency, Japan) and HFIR (Oak Ridge National Laboratory, TN, USA). Rietveld analysis was carried out for the obtained diffraction patterns using a two-phase model, which includes ices Ih and XI. The hydrogen-ordered structure in the lithium-doped ice was the same as that in the sodium-doped and potassium-doped ices. We also confirmed the optimum formation condition of ice XI for the temperature history and concentration of solution. Furthermore, our results indicate that the phase transition from ice Ih to XI occurs in the doped ice that had once been ice XI to a notably larger degree than in the doped ice that had never transformed to ice XI. We named this phenomenon memory effect of hydrogen ordering.

Oral presentation

Neutron diffraction and IR absorption studies of ice crystal; An Implication of planetary science

Arakawa, Masashi*; Kagi, Hiroyuki; Fernandez-Baca, J. A.*; Chakoumakos, B.*; Fukazawa, Hiroshi

no journal, , 

The existence of ferroelectric ice XI with ordered hydrogen in the universe becomes of interest in astronomy and physical chemistry because of the strong electric force. However, the influence seemed to be limited because it forms at narrow temperature range. From neutron diffraction experiments, we found that small hydrogen-ordered domains with ferroelectricity exist at higher temperature and the domains induce the growth of bulk ice XI. The small ordered domain is named memory of hydrogen ordered ice because it is the residual structure of ice XI.

Oral presentation

High-pressure neutron diffraction experiments at TAKUMI in J-PARC

Abe, Jun; Hattori, Takanori; Arima, Hiroshi; Sano, Asami; Fukazawa, Hiroshi; Utsumi, Wataru; Komatsu, Kazuki*; Arakawa, Masashi*; Iizuka, Riko*; Kagi, Hiroyuki*; et al.

no journal, , 

In order to confirm the feasibility of high-pressure neutron diffraction at TAKUMI, we have performed a number of R&Ds using a various high-pressure devices. Optimization of materials such as anvil and pressure medium and developments of collimators have made possible reduction of background and contamination noise. Incident and diffracted neutron beams travel through high-pressure device, which causes attenuation of neutron. We investigated the method of attenuation correction.

Oral presentation

High-pressure activities in the new pulsed neutron source J-PARC

Hattori, Takanori; Arima, Hiroshi; Sano, Asami; Abe, Jun; Honda, Mitsunori; Fukazawa, Hiroshi; Utsumi, Wataru; Okuchi, Takuo*; Ono, Yoshiki*; Sasaki, Shigeo*; et al.

no journal, , 

The high-pressure neutron experiments above 10 GPa are limited so far due to the small neutron flux, which is insufficient for tiny high-pressure sample. Recent construction of the intense pulsed neutron source around the world has changed the situation. Inspired by the new Japanese pulsed neutron source JSNS at J-PARC, we started the high-P neutron experiments at the already operated beamlines (TAKUMI, NOVA) and the construction of the new beamline dedicated for high-pressure use (PLANET). This talk introduces these activities.

25 (Records 1-20 displayed on this page)