Pressure-induced amorphization and existence of molecular and polymeric amorphous forms in dense SO2.
Proc Natl Acad Sci U S A
; 117(16): 8736-8742, 2020 Apr 21.
Article
em En
| MEDLINE
| ID: mdl-32245813
ABSTRACT
We report here the pressure-induced amorphization and reversible structural transformation between two amorphous forms of SO2 molecular amorphous and polymeric amorphous, with the transition found at 26 GPa over a broad temperature regime, 77 K to 300 K. The transformation was observed by both Raman spectroscopy and X-ray diffraction in a diamond anvil cell. The results were corroborated by ab initio molecular dynamics simulations, where both forward and reverse transitions were detected, opening a window to detailed analysis of the respective local structures. The high-pressure polymeric amorphous form was found to consist mainly of disordered polymeric chains made of three-coordinated sulfur atoms connected via oxygen atoms, with few residual intact molecules. This study provides an example of polyamorphism in a system consisting of simple molecules with multiple bonds.
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MEDLINE
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2020
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Article