Intense Reactivity in Sulfur-Hydrogen Mixtures at High Pressure under X-ray Irradiation

Edward J. Pace, Amy L. Coleman, Rachel J. Husband, Huijeong Hwang, Jinhyuk Choi, Taehyun Kim, Gilchan Hwang, Sae Hwan Chun, Daewoong Nam, Sangsoo Kim, Orianna B. Ball, Hanns Peter Liermann, Malcolm I. McMahon, Yongjae Lee, R. Stewart McWilliams

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


Superconductivity near room temperature in the sulfur-hydrogen system arises from a sequence of reactions at high pressures, with X-ray diffraction experiments playing a central role in understanding these chemical-structural transformations and the corresponding S:H stoichiometry. Here we document X-ray irradiation acting as both a probe and as a driver of chemical reaction in this dense hydride system. We observe a reaction between molecular hydrogen (H2) and elemental sulfur (S8) under high pressure, induced directly by X-ray illumination, at photon energies of 12 keV using a free electron laser. The rapid synthesis of hydrogen sulfide (H2S) at 0.3 GPa was confirmed by optical observations, spectroscopic measurements, and microstructural changes detected by X-ray diffraction. These results document X-ray induced chemical synthesis of superconductor-forming dense hydrides, revealing an alternative production strategy and confirming the disruptive nature of X-ray exposure in studies on high-pressure hydrogen chalcogenides, from water to high-temperature superconductors.

Original languageEnglish
Pages (from-to)1828-1834
Number of pages7
JournalJournal of Physical Chemistry Letters
Issue number5
Publication statusPublished - 2020 Mar 5

Bibliographical note

Funding Information:
The X-ray experiment was performed at the beamline XSS (proposal no. 2019-1st-XSS-018) at PAL-XFEL funded by the MSIP. We acknowledge Vitali Prakapenka, Sang-Heon Dan Shim, Leora Dresselhaus-Cooper, Hyunchae Cynn, Toshimori Sekine, Hae Ja Lee, and Eric Galtier for fruitful discussions, Clemens Prescher for assistance with analysis, and Hyojung Hyun for beamline assistance. Y.L. thanks the support by the Leader Researcher program (NRF-2018R1A3B1052042) of the Korean Ministry of Science, ICT and Planning (MSIP). E.J.P. and M.I.M. acknowledge support from EPSRC Grant EP/R02927X/1, and R.S.M. acknowledges support from EPSRC Grant EP/P024513/1. We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out in collaboration with PETRA III. The work by A.L.C. was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

Publisher Copyright:
© 2020 American Chemical Society.

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Physical and Theoretical Chemistry


Dive into the research topics of 'Intense Reactivity in Sulfur-Hydrogen Mixtures at High Pressure under X-ray Irradiation'. Together they form a unique fingerprint.

Cite this