Molecular Reorientation Dynamics Govern the Glass Transitions of the Amorphous Ices

• DOI: 10.1021/acs.jpclett.6b00881
• Publication Date: 2016-05-31T18:15:35Z
• Authors: J. J. Shephard; C. G. Salzmann
• Keywords: Dynamics

The glass transitions of low-density amorphous ice (LDA) and high-density (HDA) are the topic controversial discussions. Understanding their exact nature may be key to explaining anomalies liquid water but has also got implications in general context polyamorphism, occurrence multiple forms same material. We first show that transition hydrogen-disordered VI is associated with kinetic unfreezing molecular reorientation dynamics by measuring calorimetric responses corresponding H2O, H218O, D2O materials combination X-ray diffraction. Well-relaxed LDA HDA identical isotopic-response patterns calorimetry as VI, we conclude ices governed processes. This "reorientation scenario" seems resolve previously conflicting viewpoints consistent fragile-to-strong from ices.