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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Relaxation effects in low density amorphous ice: two distinct structural states observed by neutron diffraction
K Winkel1, D T Bowron, T Loerting
1Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria.
The Journal of Chemical Physics
|June 3, 2009
Summary
Investigating amorphous ices using neutron diffraction revealed distinct structures in low-density amorphous ice (LDA) samples. These structural differences, linked to water network ordering, impact compression behavior and indicate separate energy landscape basins.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Physical Chemistry
Background:
- Amorphous ices exist in various forms, including low-density amorphous ice (LDA).
- Understanding the structural nuances of LDA is crucial for comprehending water's complex phase behavior.
Purpose of the Study:
- To investigate the structural differences between two distinct LDA samples.
- To correlate these structural variations with their formation pathways and compression behaviors.
Main Methods:
- Neutron diffraction with hydrogen/deuterium (H/D) isotopic substitution.
- Preparation of LDA from high-density amorphous ice (HDA) and very high-density amorphous ice (VHDA).
- Atomistic modeling to interpret structural findings.
Main Results:
- Distinct scattering patterns were observed for the two LDA samples, indicating structural differences.
- These differences correlate with perturbations in the hydrogen-bonded water network on intermediate length scales.
- Atomistic modeling suggests a balance between short- and intermediate-range order/disorder in the LDA structures.
Conclusions:
- The structural differences in LDA samples are evident in their compression behavior.
- These findings imply the existence of distinct structural states (basins) within the LDA energy landscape, even at identical densities.
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