First principles study of dense and metallic nitric sulfur hydrides
| Autor: | Lewis Conway, Maosheng Miao, Angus Lowe, Xiaofeng Li, Andreas Hermann |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Superconductivity
Materials science Hydrogen sulfide Mixing (process engineering) chemistry.chemical_element General Chemistry 01 natural sciences Biochemistry Sulfur Crystal structure prediction Metal Ammonia chemistry.chemical_compound Chemistry chemistry Chemical physics Phase (matter) visual_art 0103 physical sciences Materials Chemistry visual_art.visual_art_medium Environmental Chemistry 010306 general physics 010303 astronomy & astrophysics QD1-999 |
| Zdroj: | Li, X, Lowe, A, Conway, L, Miao, M & Hermann, A 2021, ' First principles study of dense and metallic nitric sulfur hydrides ', Communications Chemistry, vol. 4, 83, pp. 1-10 . https://doi.org/10.1038/s42004-021-00517-y Communications Chemistry, Vol 4, Iss 1, Pp 1-10 (2021) |
| Popis: | Studies of molecular mixtures containing hydrogen sulfide (H2S) could open up new routes towards hydrogen-rich high-temperature superconductors under pressure. H2S and ammonia (NH3) form hydrogen-bonded molecular mixtures at ambient conditions, but their phase behavior and propensity towards mixing under pressure is not well understood. Here, we show stable phases in the H2S–NH3 system under extreme pressure conditions to 4 Mbar from first-principles crystal structure prediction methods. We identify four stable compositions, two of which, (H2S) (NH3) and (H2S) (NH3)4, are stable in a sequence of structures to the Mbar regime. A re-entrant stabilization of (H2S) (NH3)4 above 300 GPa is driven by a marked reversal of sulfur-hydrogen chemistry. Several stable phases exhibit metallic character. Electron–phonon coupling calculations predict superconducting temperatures up to 50 K, in the Cmma phase of (H2S) (NH3) at 150 GPa. The present findings shed light on how sulfur hydride bonding and superconductivity are affected in molecular mixtures. They also suggest a reservoir for hydrogen sulfide in the upper mantle regions of icy planets in a potentially metallic mixture, which could have implications for their magnetic field formation. |
| Databáze: | OpenAIRE |
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