TY - JOUR
T1 - Ice Ic without stacking disorder by evacuating hydrogen from hydrogen hydrate
AU - Komatsu, Kazuki
AU - Machida, Shinichi
AU - Noritake, Fumiya
AU - Hattori, Takanori
AU - Sano-Furukawa, Asami
AU - Yamane, Ryo
AU - Yamashita, Keishiro
AU - Kagi, Hiroyuki
N1 - Funding Information:
We are grateful to Drs. J. Abe and K. Funakoshi for their assistance with the experiments, and to anonymous reviewers for their valuable comments, particularly on the relation with anomalous preservation of gas hydrates. Neutron diffraction experiments were performed through the J-PARC user programs (Nos. 2014B0187, 2015A0033, 2017A0092, 2017B0031). X-ray diffraction experiments were performed under the approval of the Photon Factory Program Advisory Committee (Proposal Nos. 2016G107, 2018G656). This study was supported by JSPS KAKENHI (Grant Numbers: 18H05224, 18H01936, 15H05829).
Publisher Copyright:
© 2020, The Author(s).
PY - 2020/12/1
Y1 - 2020/12/1
N2 - 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 hydrogen from the high-pressure form of hydrogen hydrate, C2, which has a host framework isostructural with ice Ic. The stacking-disorder free ice Ic is formed from C2 via an intermediate amorphous or nano-crystalline form under decompression, unlike the direct transformations occurring in ice XVI from neon hydrate, or ice XVII from hydrogen hydrate. The obtained ice Ic shows remarkable thermal stability, until the phase transition to ice Ih at 250 K, originating from the lack of dislocations. This discovery of ideal ice Ic will promote understanding of the role of stacking-disorder on the physical properties of ice as a counter end-member of ice Ih.
AB - 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 hydrogen from the high-pressure form of hydrogen hydrate, C2, which has a host framework isostructural with ice Ic. The stacking-disorder free ice Ic is formed from C2 via an intermediate amorphous or nano-crystalline form under decompression, unlike the direct transformations occurring in ice XVI from neon hydrate, or ice XVII from hydrogen hydrate. The obtained ice Ic shows remarkable thermal stability, until the phase transition to ice Ih at 250 K, originating from the lack of dislocations. This discovery of ideal ice Ic will promote understanding of the role of stacking-disorder on the physical properties of ice as a counter end-member of ice Ih.
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U2 - 10.1038/s41467-020-14346-5
DO - 10.1038/s41467-020-14346-5
M3 - Article
C2 - 32015342
AN - SCOPUS:85078876813
VL - 11
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
IS - 1
M1 - 464
ER -