Hydrogen sulfide at high pressure: change in stoichiometry
ORAL
Abstract
Hydrogen sulfide (H$_{\mathrm{2}}$S) was studied by x-ray synchrotron diffraction (XRD) and Raman spectroscopy up to 144 GPa at 180-295 K. We find that H$_{\mathrm{2}}$S compound become unstable with respect to formation of new compounds with different composition including pure S, H$_{\mathrm{3}}$S and HS$_{\mathrm{2}}$ depending on the thermodynamic P-T path. These results are supported by our quantum-mechanical variable-composition evolutionary simulations that show the stability of the above mentioned compounds at elevated pressures. The stability of H$_{\mathrm{3}}$S at high pressures, which we find a strong experimental and theoretical confirmation here, suggests that it is this material which is responsible for high-temperature superconducting properties reported previously.
*We thank DARPA, NSF, ISSP (Hefei, China), Government of Russian Federation, and Foreign Talents Introduction and Academic Exchange Program. Use of the Advanced Photon Source was supported by the U. S. Department of Energy Office of Science
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