Superconductivity up to 243 K in the yttrium-hydrogen system under high pressure.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34417471.
- Also identified by DOI 10.1038/s41467-021-25372-2 and PMC identifier 8379216.
- 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
The discovery of superconducting H<sub>3</sub>S with a critical temperature T<sub>c</sub>∼200 K opened a door to room temperature superconductivity and stimulated further extensive studies of hydrogen-rich compounds stabilized by high pressure. Here, we report a comprehensive study of the yttrium-hydrogen system with the highest predicted T<sub>c</sub>s among binary compounds and discuss the contradictions between different theoretical calculations and experimental data. We synthesized yttrium hydrides with the compositions of YH<sub>3</sub>, YH<sub>4</sub>, YH<sub>6</sub> and YH<sub>9</sub> in a diamond anvil cell and studied their crystal structures, electrical and magnetic transport properties, and isotopic effects. We found superconductivity in the Im-3m YH<sub>6</sub> and P6<sub>3</sub>/mmc YH<sub>9</sub> phases with maximal T<sub>c</sub>s of ∼220 K at 183 GPa and ∼243 K at 201 GPa, respectively. Fm-3m YH<sub>10</sub> with the highest predicted T<sub>c </sub>> 300 K was not observed in our experiments, and instead, YH<sub>9</sub> was found to be the hydrogen-richest yttrium hydride in the studied pressure and temperature range up to record 410 GPa and 2250 K.