Synthesis of molecular metallic barium superhydride: pseudocubic BaH12
| Autor: | Alexander G. Kvashnin, Hao Song, Alexander F. Goncharov, Michele Galasso, Wuhao Chen, Defang Duan, Vitali B. Prakapenka, Artem R. Oganov, Xiaoli Huang, Tian Cui, Ivan A. Kruglov, Dmitrii V. Semenok |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Hydrogen Science General Physics and Astronomy chemistry.chemical_element 02 engineering and technology 01 natural sciences General Biochemistry Genetics and Molecular Biology Metal Ab initio quantum chemistry methods Impurity 0103 physical sciences 010306 general physics Superconductivity Multidisciplinary Hydride Barium General Chemistry 021001 nanoscience & nanotechnology chemistry Chemical physics visual_art visual_art.visual_art_medium Density functional theory 0210 nano-technology |
| Zdroj: | Nature Communications, Vol 12, Iss 1, Pp 1-9 (2021) |
| ISSN: | 2041-1723 |
| Popis: | Following the discovery of high-temperature superconductivity in the La–H system, we studied the formation of new chemical compounds in the barium-hydrogen system at pressures from 75 to 173 GPa. Using in situ generation of hydrogen from NH3BH3, we synthesized previously unknown superhydride BaH12 with a pseudocubic (fcc) Ba sublattice in four independent experiments. Density functional theory calculations indicate close agreement between the theoretical and experimental equations of state. In addition, we identified previously known P6/mmm-BaH2 and possibly BaH10 and BaH6 as impurities in the samples. Ab initio calculations show that newly discovered semimetallic BaH12 contains H2 and H3– molecular units and detached H12 chains which are formed as a result of a Peierls-type distortion of the cubic cage structure. Barium dodecahydride is a unique molecular hydride with metallic conductivity that demonstrates the superconducting transition around 20 K at 140 GPa. |
| Databáze: | OpenAIRE |
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