Synthesis of clathrate cerium superhydride CeH<sub>9</sub> at 80-100 GPa with atomic hydrogen sublattice.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31575861.
- Also identified by DOI 10.1038/s41467-019-12326-y and PMC identifier 6773858.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Hydrogen-rich superhydrides are believed to be very promising high-T<sub>c</sub> superconductors. Recent experiments discovered superhydrides at very high pressures, e.g. FeH<sub>5</sub> at 130 GPa and LaH<sub>10</sub> at 170 GPa. With the motivation of discovering new hydrogen-rich high-T<sub>c</sub> superconductors at lowest possible pressure, here we report the prediction and experimental synthesis of cerium superhydride CeH<sub>9</sub> at 80-100 GPa in the laser-heated diamond anvil cell coupled with synchrotron X-ray diffraction. Ab initio calculations were carried out to evaluate the detailed chemistry of the Ce-H system and to understand the structure, stability and superconductivity of CeH<sub>9</sub>. CeH<sub>9</sub> crystallizes in a P6<sub>3</sub>/mmc clathrate structure with a very dense 3-dimensional atomic hydrogen sublattice at 100 GPa. These findings shed a significant light on the search for superhydrides in close similarity with atomic hydrogen within a feasible pressure range. Discovery of superhydride CeH<sub>9</sub> provides a practical platform to further investigate and understand conventional superconductivity in hydrogen rich superhydrides.