Local electronic structure rearrangements and strong anharmonicity in YH<sub>3</sub> under pressures up to 180 GPa.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33741970.
- Also identified by DOI 10.1038/s41467-021-21991-x and PMC identifier 7979761.
- 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 superconductivity above 250 K at high pressure in LaH<sub>10</sub> and the prediction of overcoming the room temperature threshold for superconductivity in YH<sub>10</sub> urge for a better understanding of hydrogen interaction mechanisms with the heavy atom sublattice in metal hydrides under high pressure at the atomic scale. Here we use locally sensitive X-ray absorption fine structure spectroscopy (XAFS) to get insight into the nature of phase transitions and the rearrangements of local electronic and crystal structure in archetypal metal hydride YH<sub>3</sub> under pressure up to 180 GPa. The combination of the experimental methods allowed us to implement a multiscale length study of YH<sub>3</sub>: XAFS (short-range), Raman scattering (medium-range) and XRD (long-range). XANES data evidence a strong effect of hydrogen on the density of 4d yttrium states that increases with pressure and EXAFS data evidence a strong anharmonicity, manifested as yttrium atom vibrations in a double-well potential.