Structure of amorphous non-molecular CS<sub>2</sub> at high pressure - experiment and simulation

ORAL

Abstract

CS2 represents an important simple molecular system with double bonds. It is widely believed that upon compression it converts into a system of (-(C=S)-S-)n polymeric chains (Bridgman's black polymer-BBP). Here we show, combining new Raman, IR and XRD data for pressures up to 40 GPa with ab initio and machine-learned potential simulations, that the structure of BBP is different. Pressure-induced polymerization creates an amorphous system consisting of chains with 3-coordinated C atoms connected via S bridges or double C=C bonds as well as ones with 4-coordinated C atoms within edge-sharing CS4 tetrahedra. Spectral features observed upon compression can be explained without need for decomposition of molecules. Upon decompression, partially reversible transition is observed. Our work uncovers the non-trivial high-pressure structural evolution in one of the simplest and long-studied molecular systems.

*CAS President’s International Fellowship Initiative Fund (2018VMA0053, 2019VMA0027), National Natural Science Foundation of China Grant (11874361, 51672279, 11774354, 51727806), CAS Innovation Grant (CXJJ-19-B08), Science Challenge Project (TZ2016001), Hefei Institutes of Physical Science CAS Director’s Fund Grant (YZJJ2017705), Slovak Research and Development Agency grant APVV-19-0371

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Presenters

  • Ondrej Tóth

    • Department of Experimental Physics, Comenius Univ, Bratislava, Slovakia
    • Department of experimental physics, Comenius university

Authors

  • Jinwey Yan

    • Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences

  • Ondrej Tóth

    • Department of Experimental Physics, Comenius Univ, Bratislava, Slovakia
    • Department of experimental physics, Comenius university

  • Wan Xu

    • Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences

  • Xiao-Di Liu

    • Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, China
    • Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences

  • Eugene Gregoryanz

    • Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, China
    • Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences

  • Philip Dalladay-Simpson

    • Center for High Pressure Science Technology Advanced Research, Shanghai, China
    • Center for High Pressure Science Technology Advanced Research

  • Mario Santoro

    • National Institute of Optics, CNR-INO, and European Laboratory for Non-Linear Spectroscopy, LENS, Sesto Fiorentino, Italy
    • European Laboratory for Non-Linear Spectroscopy

  • Federico Aiace Gorelli

    • National Institute of Optics, CNR-INO, and European Laboratory for Non-Linear Spectroscopy, LENS, Sesto Fiorentino, Italy
    • European Laboratory for Non-Linear Spectroscopy

  • Roman Martonak

    • Department of Experimental Physics, Comenius Univ, Bratislava, Slovakia
    • Department of experimental physics, Comenius university