Probing Medium-Range Order in Oxide Glasses at High Pressure.
The Journal of Physical Chemistry Letters
|January 27, 2021
Summary
Densification in borate glasses under pressure leads to a more homogeneous distribution of structural units. This increased medium-range disorder is directly linked to glass densification under extreme compression.
Area of Science:
- Materials Science
- Solid State Chemistry
- Physical Chemistry
Background:
- Traditional densification models focus on short-range atomic structures.
- Experimental verification of medium-range structural changes during densification remains challenging.
Purpose of the Study:
- To investigate pressure-induced structural evolution in borate glasses.
- To understand medium-range structural changes impacting glass densification.
Main Methods:
- Utilized correlation Nuclear Magnetic Resonance (NMR) spectroscopy.
- Applied extreme compression up to 9 GPa to prototypical borate glasses.
Main Results:
- Observed decreased segregation of similar coordination species with increasing pressure.
- Found a more homogeneous distribution of dissimilar structural units under compression.
- Linked increased medium-range disorder to densification and increased configurational entropy.
Conclusions:
- Densification of borate glasses under pressure involves a shift towards random distribution of structural units.
- Medium-range structural disorder plays a crucial role in glass densification under extreme conditions.
