Diffusive dynamics during the high-to-low density transition in amorphous ice
Abstract
The importance of a molecular-level understanding of the properties, structure, and dynamics of liquid water is recognized in many scientific fields. It has been debated whether the observed high- and low-density amorphous ice forms are related to two distinct liquid forms. Here, we study experimentally the structure and dynamics of high-density amorphous ice as it relaxes into the low-density form. The unique aspect of this work is the combination of two X-ray methods, where wide-angle X-ray scattering provides the evidence for the structure at the atomic level and X-ray photon-correlation spectroscopy provides insight about the motion at the nanoscale, respectively. The observed motion appears diffusive, indicating liquid-like dynamics during the relaxation from the high-to low-density form.
- Publication:
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Proceedings of the National Academy of Science
- Pub Date:
- August 2017
- DOI:
- 10.1073/pnas.1705303114
- Bibcode:
- 2017PNAS..114.8193P
- Keywords:
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- liquid–liquid transition;
- glass transition;
- amorphous ice;
- X-ray photon-correlation spectroscopy;
- supercooled water