2023/04/18 by P. F. Shan, Shan, P. F., T. L. Lu +30 · 1 voice · 1 citation
Materials Science · Physics and Astronomy · #Thermal Expansion and Ionic Conductivity #Superconductivity in MgB2 and Alloys #Rare-earth and actinide compounds
paper · pdf · doi:10.1093/nsr/nwag425
Abstract As an A-site-vacant perovskite-type oxide, ReO3 undergoes sequential pressure-driven structural phase transitions associated with rotations of ReO6 octahedra. In this work, we report the discovery of a superconducting Tc(P) dome for the rhombohedral-I phase of ReO3 in the pressure range 12-39 GPa. The rhombohedral-I phase is featured by the nearly close-packed oxygen layers intercalated with Re cations, which is reminiscent of superhydride superconductors. The observed maximum Tc ∼ 17.8 K sets the record of high Tc among 5d transition-metal-oxides. First-principles calculations reveal that the strong hybridizations between Re-5d and O-2p orbitals significantly enhance the density of states at the Fermi level and the close-packed oxygen framework directly enhances the electron-phonon coupling. We attributed the observed record high-Tc to the synergistic effect of strong hybridizations and oxygen sublattice contribution. The present work establishes a rare case that the light-element oxygen lattice plays a crucial role in assisting the emergence of high-Tc superconductivity and provides more clues for further exploring new superconductors in 5d transition-metal oxides via high-pressure or heterostructure engineering.