Skip to main content

Structural characterization of ice XIX as the second polymorph related to ice VI

5Citations
Citations of this article
11Readers
Mendeley users who have this article in their library.

This artice is free to access.

Abstract

Ice polymorphs usually appear as hydrogen disorder-order pairs. Ice VI has a wide range of thermodynamic stability and exists in the interior of Earth and icy moons. Our previous work suggested ice β-XV as a second polymorph deriving from disordered ice VI, in addition to ice XV. Here we report thermal and structural characterization of the previously inaccessible deuterated polymorph using ex situ calorimetry and high-resolution neutron powder diffraction. Ice β-XV, now called ice XIX, is shown to be partially antiferroelectrically ordered and crystallising in a √2×√2×1 supercell. Our powder data recorded at subambient pressure fit best to the structural model in space group P4 ¯. Key to the synthesis of deuterated ice XIX is the use of a DCl-doped D2O/H2O mixture, where the small H2O fraction enhances ice XIX nucleation kinetics. In addition, we observe the transition from ice XIX to its sibling ice XV upon heating, which proceeds via a transition state (ice VI‡) containing a disordered H-sublattice. To the best of our knowledge this represents the first order-order transition known in ice physics.

Cite

CITATION STYLE

APA

Gasser, T. M., Thoeny, A. V., Fortes, A. D., & Loerting, T. (2021). Structural characterization of ice XIX as the second polymorph related to ice VI. Nature Communications, 12(1). https://doi.org/10.1038/s41467-021-21161-z

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free