Local electronic structure rearrangements and strong anharmonicity in YH3 under pressures up to 180 GPa

• Published in: Nature communications Vol. 12; no. 1; pp. 1765 - 10
• Main Authors: Purans, J., Menushenkov, A. P., Besedin, S. P., Ivanov, A. A., Minkov, V. S., Pudza, I., Kuzmin, A., Klementiev, K. V., Pascarelli, S., Mathon, O., Rosa, A. D., Irifune, T., Eremets, M. I.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19.03.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/119/995; 639/766/119/1003; Anharmonicity; Condensed Matter Physics; Condensed Matter Physics (including Material Physics, Nano Physics); Crystal structure; Den kondenserade materiens fysik; Den kondenserade materiens fysik (Här ingår: Materialfysik, nanofysik); Density; Electronic structure; Experimental methods; Fine structure; Fysik; Heavy metals; High pressure; Humanities and Social Sciences; Hydrogen; Metal hydrides; multidisciplinary; Natural Sciences; Naturvetenskap; Phase transitions; Physical Sciences; Pressure; Raman spectra; Room temperature; Science; Science (multidisciplinary); Spectroscopy; Superconductivity; Ultrastructure; Vibrations; X ray absorption; Yttrium
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-21991-x

The discovery of superconductivity above 250 K at high pressure in LaH 10 and the prediction of overcoming the room temperature threshold for superconductivity in YH 10 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 3 under pressure up to 180 GPa. The combination of the experimental methods allowed us to implement a multiscale length study of YH 3 : XAFS (short-range), Raman scattering (medium-range) and XRD (long-range). XANES data evidence a strong effect of hydrogen on the density of 4 d yttrium states that increases with pressure and EXAFS data evidence a strong anharmonicity, manifested as yttrium atom vibrations in a double-well potential. The discovery of superconductivity in metal hydrides requires an understanding of hydrogen interactions with the heavy atom sublattice under high pressure. Here, the authors report evidence of a strong effect of hydrogen on the density increase of 4 d yttrium states and strong anharmonic vibrations of yttrium atoms in YH 3 .