Work

Beyond sixfold coordinated Si in SiO 2 glass at ultrahigh pressures

Year: 2017

Type: article

Abstract: first undergoes a change in Si-O coordination number from fourfold to sixfold between 15 and 50 GPa, in agreement with previous investigations. Above 50 GPa, the estimated coordination number continuously increases from 6 to 6.8 at 172 GPa. Si-O bond length shows first an increase due to the fourfold to sixfold coordination change and then a smaller linear decrease up to 172 GPa. We reconcile the changes in relation to the oxygen-packing fraction, showing that oxygen packing decreases at ultrahigh pressures to accommodate the higher than sixfold Si-O coordination. These results give experimental insight into the structural changes of silicate glasses as analogue materials for silicate melts at ultrahigh pressures.

Source: Proceedings of the National Academy of Sciences

DOI: 10.1073/pnas.1708882114

Authors: Clemens Prescher, Vitali B. Prakapenka, Johannes Stefanski, Sandro Jahn, Lawrie B. Skinner, Yanbin Wang

Institutions: University of Cologne, University of Chicago, Argonne National Laboratory, Advanced Photon Source, Stony Brook University

Language: English

Topic: High-pressure geophysics and materials

Subfield: Geophysics

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: green

Funder: National Science Foundation

OpenAlex ID: W2753685605

FWCI: 8.008

Cites: 54

Cited by: 127

Related to: 10