High-pressure structural changes in liquid silica.
A Denoeud1,2, S Mazevet3,4, F Guyot5
1LULI-CNRS, Ecole Polytechnique, CEA, Université Paris-Saclay, F-91128 Palaiseau cedex, France.
Physical Review. E
|October 15, 2016
Summary
Researchers studied liquid silica under high pressure and moderate temperatures. They found its structure becomes similar to solid silica phases as density increases, with silicon
Area of Science:
- Materials Science
- High-Pressure Physics
- Plasma Physics
Background:
- Understanding the behavior of materials under extreme conditions is crucial for various scientific fields.
- Liquid silica (SiO2) under warm dense matter conditions presents unique structural challenges.
Purpose of the Study:
- To investigate the structural properties of liquid silica at high pressures and moderate temperatures.
- To determine how density affects the coordination number of silicon in liquid silica.
Main Methods:
- Utilized time-resolved K-edge X-ray absorption spectroscopy.
- Employed nanosecond and picosecond lasers for compression and X-ray generation.
- Performed ab initio calculations for theoretical interpretation.
Main Results:
- Observed liquid silica up to 3.6 times normal solid density.
- Interpreted X-ray absorption near-edge structure changes with increasing density.
- Determined an increase in silicon's coordination number from 4 to 9.
Conclusions:
- The structure of liquid silica transitions towards solid-like phases at high densities and temperatures.
- Coordination number increase indicates a significant structural change under compression.
- Ab initio simulations successfully explained the experimental spectroscopic data.
