Proton Ordering of Cubic Ice Ic

Autor(en)

Philipp Geiger, Christoph Dellago, Markus Macher, Cesare Franchini, Georg Kresse, Juergen Bernard, Josef N. Stern, Thomas Loerting

Abstrakt

Several proton-disordered crystalline ice structures are known to proton order at sufficiently low temperatures, provided that the right preparation procedure is used. For cubic ice, ice Ic, however, no proton ordering has been observed so far. Here, we subject ice Ic to an experimental protocol similar to that used to proton order hexagonal ice. In situ FT-IR spectroscopy carried out during this procedure reveals that the librational band of the spectrum narrows and acquires a structure that is observed neither in proton-disordered ice Ic nor in ice XI, the proton-ordered variant of hexagonal ice. On the basis of vibrational spectra computed for ice Ic and four of its proton-ordered variants using classical molecular dynamics and ab initio simulations, we conclude that the features of our experimental spectra are due to partial proton ordering, providing the first evidence of proton ordering in cubic ice. We further find that the proton-ordered structure with the lowest energy is ferroelectric, while the structure with the second lowest energy is weakly ferroelectric. Both structures fit the experimental spectral similarly well such that no unique assignment of proton order is possible based on our results.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie, Institut für Lehrer*innenbildung, Computergestützte Materialphysik

Externe Organisation(en)

Leopold-Franzens-Universität Innsbruck, Universität Wien

Journal

The Journal of Physical Chemistry Part C (Nanomaterials and Interfaces)

Band

118

Seiten

10989-10997

Anzahl der Seiten

9

ISSN

1932-7447

DOI

https://doi.org/10.1021/jp500324x

Publikationsdatum

05-2014

Peer-reviewed

Ja

ÖFOS 2012

103009 Festkörperphysik, 103015 Kondensierte Materie, 103025 Quantenmechanik, 103036 Theoretische Physik

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/e728faf3-33a5-42c2-97bf-2d2e7454e2f9