Abstract
The pressure-temperature phase diagram of ice displays a perplexing variety of structurally distinct phases. In the century-long history of scientific research on ice, the proton-ordered ice phases numbered XIII through XV were discovered only recently. Despite considerable effort, none of the transitions leading from the low-temperature ordered ices VIII, IX, XI, XIII, XIV and XV to their high-temperature disordered counterparts were experimentally found to display the full Pauling entropy. Here we report calorimetric measurements on suitably high-pressure-treated, hydrogen chloride-doped ice XIV that demonstrate just this at the transition to ice XII. Dielectric spectroscopy on undoped and on variously doped ice XII crystals reveals that addition of hydrogen chloride, the agent triggering complete proton order in ice XIV, enhances the precursor dynamics strongest. These discoveries provide new insights into the puzzling observation that different dopants trigger the formation of different proton-ordered ice phases.
Original language | English |
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Article number | 7349 |
Journal | Nature Communications |
Volume | 6 |
DOIs | |
State | Published - Jun 16 2015 |
Externally published | Yes |
Funding
We thank B. Geil for stimulating discussions. Support of this project by the Deutsche Forschungsgemeinschaft (DFG) under grant number BO1301/12-1, the Austrian Science Fund (FWF), project I1392 and the Alexander von Humboldt Foundation, through the Friedrich Wilhelm Bessel Research Award to T.L., are gratefully acknowledged.
Funders | Funder number |
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Alexander von Humboldt-Stiftung | |
Deutsche Forschungsgemeinschaft | BO1301/12-1 |
Austrian Science Fund | I1392 |