Dissociation products and structures of solid H2S at strong compression
Physical Review B
American Physical Society
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Li, Y., Wang, L., Liu, H., Zhang, Y., Hao, J., Pickard, C., Nelson, J., et al. (2016). Dissociation products and structures of solid H2S at strong compression. Physical Review B, 93 (020103(R))https://doi.org/10.1103/PhysRevB.93.020103
Hydrogen sulfides have recently received a great deal of interest due to the record high superconducting temperatures of up to 203 K observed on strong compression of dihydrogen sulfide (H2S). A joint theoretical and experimental study is presented in which decomposition products and structures of compressed H2S are characterized, and their superconducting properties are calculated. In addition to the experimentally known H2S and H3S phases, our first-principles structure searches have identified several energetically competitive stoichiometries that have not been reported previously: H2S3, H3S2, HS2, and H4S3. In particular, H4S3 is predicted to be thermodynamically stable within a large pressure range of 25–113 GPa. High-pressure X-ray diffraction measurements confirm the presence of H3S and H4S3 through decomposition of H2S that emerges at 27 GPa and coexists with residual H2S, at least up to the highest pressure studied in our experiments of 140 GPa. Electron-phonon coupling calculations show that H4S3 has a small T_c of below 2 K, and that H2S is mainly responsible for the observed superconductivity of samples prepared at low temperature (<100K).
Y. L. and J. H. acknowledge funding from the National Natural Science Foundation of China under Grant No. 11204111 and No. 11404148, the Natural Science Foundation of Jiangsu province under Grant No. BK20130223, and the PAPD of Jiangsu Higher Education Institutions. Y. Z. and Y. M. acknowledge funding from the National Natural Science Foundation of China under Grant Nos. 11274136 and 11534003, the 2012 Changjiang Scholars Program of China. R. J. N. acknowledges financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the U.K. [EP/J017639/1]. Calculations were performed on the Cambridge High Performance Computing Service facility and the HECToR and Archer facilities of the U.K.’s national highperformance computing service (for which access was obtained via the UKCP consortium [EP/K013564/1]). J. R. N. acknowledges financial support from the Cambridge Commonwealth Trust. I. E. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (FIS2013-48286-C2-2-P). M. C. acknowledges support from the Graphene Flagship and Agence nationale de la recherche (ANR), Grant No. ANR-13-IS10- 0003-01. Work at Carnegie was partially supported by EFree, an Energy Frontier Research Center funded by the DOE, Office of Science, Basic Energy Sciences under Award No. DE-SC-0001057 (salary support for H. L.). The infrastructure and facilities used at Carnegie were supported by NNSA Grant No. DE-NA-0002006, CDAC.
External DOI: https://doi.org/10.1103/PhysRevB.93.020103
This record's URL: https://www.repository.cam.ac.uk/handle/1810/253226