Ryo Yamane's research while affiliated with Tohoku University and other places

Publications (14)

Article
We have conducted dielectric measurements of ice VII at pressures up to 12.2 GPa, and verified a dominant-dynamics change from a molecular rotation to a proton translation at approximately 10 GPa, using a newly developed high-pressure cell. Based on relaxation times of the two motions, which have a crossover point between 9 and 10 GPa, we show that...
Article
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A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-22085-4
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Ice exhibits extraordinary structural variety in its polymorphic structures. The existence of a new form of diversity in ice polymorphism has recently been debated in both experimental and theoretical studies, questioning whether hydrogen-disordered ice can transform into multiple hydrogen-ordered phases, contrary to the known one-to-one correspond...
Preprint
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More than 20 crystalline and amorphous phases have been reported for ice so far. This extraordinary polymorphism of ice arises from the geometric flexibility of hydrogen bonds and hydrogen ordering, and makes ice a unique presence with its universality in the wide fields of material and earth and planetary science. A prominent unsolved question con...
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Water freezes below 0 °C at ambient pressure ordinarily to ice Ih, with hexagonal stacking sequence. Under certain conditions, ice with a cubic stacking sequence can also be formed, but ideal ice Ic without stacking-disorder has never been formed until recently. Here we demonstrate a route to obtain ice Ic without stacking-disorder by degassing hyd...
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Water freezes below 0 {\deg}C at ambient pressure, ordinarily to ice Ih with an ABAB... hexagonal stacking sequence. However, it is also known to produce "ice Ic" nominally with an ABCABC... cubic stacking sequence under certain conditions1, and its existence in Earth's atmosphere, or in comets is debated. "Ice Ic", or called as cubic ice, was firs...
Article
Neutron diffraction experiments of ice VII at pressures up to 6.2 GPa and 10.2 kV/mm were conducted to investigate the potential ferroelectrically ordered structure of ice VII induced by a high electric field. To accomplish this, we developed a high-pressure cell assembly to allow for powder neutron diffraction to be conducted under both high-press...
Article
Here I discuss a problem of an inconsistency among various experiments and calculations for ice XV, the ordered form of ice VI, i.e., neutron diffraction observations suggest antiferroelectrically ordered structures, which disagree with dielectric measurement and theoretical studies, implying ferroelectrically ordered structures. Our recent neutron...
Article
We developed a new high pressurecell which allows us to perform accurate dielectric measurements above 3 GPa. The developed cell is based on Bridgman type opposed anvil cells with electrodes immersed into holes in the anvils in order to make the electrode area constant under compression. As a feasibility experiment, dielectric measurements for H2O...
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Scientific Reports 6 : Article number: 28920; 10.1038/srep28920 published online: 04 July 2016 ; updated: 12 August 2016 . The original version of this Article incorrectly listed ‘School of Material and Chemical Technology, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-Ku, Tokyo 152-8550, Japan’ as a present address for K.
Article
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Most ice polymorphs have order–disorder “pairs” in terms of hydrogen positions, which contributes to the rich variety of ice polymorphs; in fact, three recently discovered polymorphs— ices XIII, XIV, and XV—are ordered counter forms to already identified disordered phases. Despite the considerable effort to understand order–disorder transition in i...

Citations

... Although this consistency strongly supports Pruzan's scenario, no direct evidence for the cross-over of proton dynamics was provided until recently. Yamane et al. used their own developed high-P cell to conduct dielectric measurements up to 12.2 GPa and were able to directly detect the cross-over of two dielectric relaxations corresponding to rotation and translational motions at around 10 GPa [255]. This would be the most conclusive result to explain the long-standing problem of the anomalous behaviour of ice VII. ...
... Ice XVIII was created under extreme high-temperature and high-pressure conditions of more than 100 GPa and 2000 K using laser-driven shock compression experiments, and the fcc structure was determined using x-ray diffraction [25]. 3 Two independent groups, Yamane et al. [26] and Gasser et al. [27], have identified the most recently discovered ice polymorph, ice XIX. 4 Ice XIX may be a second partiallyordered phase of ice VI, but the details of its structure remain debatable, as discussed in chapter 4.6.3. ...
... Following that, in 2016, del Rosso et al. reported ice XVII, which was obtained by the same method as ice XVI, but by removing hydrogen from hydrogen hydrate [22]. More recently, Komatsu et al. [23] and del Rosso et al. [24] reported that ice I c with no stacking disorder can be synthesized by removing hydrogen or decomposing from various hydrogen hydrates, as discussed in chapter 4.1.2. Ice XVIII was created under extreme high-temperature and high-pressure conditions of more than 100 GPa and 2000 K using laser-driven shock compression experiments, and the fcc structure was determined using x-ray diffraction [25]. ...
... Yamane et al. developed a high-P cell assembly for powder neutron diffraction under both high-P and high-electric field (E) to explore the potentially existing ferroelectrically ordered form of ice VII [100]. Although the known ordered form of ice VII is an antiferroelectrically ordered ice VIII, several theoretical studies suggest that other ordered form configurations may have competitive free energies [101,102]. ...
... Finally, the future outlook is discussed, including potentially existing ice polymorphs expected from computational approaches using novel techniques with various neutron scattering to find their new phases. This review is based on my previous articles [37][38][39][40], but with significant changes and additions. ...
... Electric polarization was measured at high pressure by using a differentcell assembly, improved from our previous development using hole-type opposed anvils (see [21] and the Supplemental Material [22]). A notable feature of this cell is that only the sample is sandwiched by electrodes, and this feature allow us to measure induced charge on the electrodes derived from the sample. ...
... For ice VI, I have discovered that the graphical representation is very useful for counting order structures . In fact, representing ice VI as an undirected graph results in a complete graph known as K 5 ( Figure 13) [140]. A complete graph is a simple undirected graph in which each pair of distinct vertices is connected by a unique edge, and K n denotes a complete graph with n vertices. ...