2019/01/13 by Christoph Heil, Simone Di Cataldo, Simone di Cataldo +8 · 4 citations
Chemistry · Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #Ab initio #Chemistry #Condensed matter physics #Coulomb #Electron #Ferrimagnetism #High-pressure geophysics and materials #Magnetization #Materials science #Nuclear Materials and Properties #Oxide #Physics #Pseudopotential #Quantum mechanics #Rare-earth and actinide compounds #Sodalite #Superconductivity #Yttrium #cond-mat.mtrl-sci #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.99.220502
published as Phys. Rev. B 99, 220502 (2019)
arxiv created 2019/01/13 · openalex publication_date 2019/06/10 · arxiv updated 2019/06/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Motivated by the discovery of near-room-temperature superconductivity in the sodalite-like clathrate hydride LaH10, we report ab initio calculations of the superconducting properties of two closely related hydrides YH6 and YH10 for which an even higher Tc has been predicted. Using fully anisotropic Migdal-Eliashberg theory with Coulomb corrections, we find almost isotropic superconducting gaps, resulting from a uniform distribution of the coupling over states of both Y and H sublattices. The Coulomb screening is rather weak, resulting in a Morel-Anderson pseudopotential \ensuremathμ*=0.11, at odds with claims of unusually large \ensuremathμ* in lanthanum hydrides. The corresponding critical temperatures at 300 GPa exceed room temperature (Tc=290 and 310 K for YH6 and YH10), in agreement with a previous isotropic-gap calculation. We estimate anharmonic effects to be weak. The different response of these two compounds to external pressure along with a comparison to low-Tc superconducting YH3 may inspire strategies to improve the superconducting properties of this class of hydrides.