Partially ordered state of ice XV

K. Komatsu, F. Noritake, S. Machida, A. Sano-Furukawa, T. Hattori, R. Yamane, H. Kagi

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)

Abstract

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 ice crystals, there is an inconsistency among the various experiments and calculations for ice XV, the ordered counter 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. Here 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 n possible configurations at finite temperature.

Original languageEnglish
Article number28920
JournalScientific reports
Volume6
DOIs
Publication statusPublished - 2016 Jul 4
Externally publishedYes

ASJC Scopus subject areas

  • General

Fingerprint

Dive into the research topics of 'Partially ordered state of ice XV'. Together they form a unique fingerprint.

Cite this