ic7b01686_si_001.pdf (1.19 MB)
Superconductivity of Pressure-Stabilized Vanadium Hydrides
journal contribution
posted on 2017-11-02, 15:49 authored by Xiaofeng Li, Feng PengThe study of the high-temperature
superconductive property in compressed hydrogen (H)-rich hydrides
has been motivated by hydrides, which become superconducting at low
pressure due to chemical precompression. In the present study, we
report the first-principles structure searches for stable vanadium(V)
hydrides over a pressure scope 0–200 GPa, where stable unexpected
stoichiometries of H-rich V hydrides (e.g., VH3, VH5, and VH8) emerge. These dense H-rich V hydrides
are metallic with a strong ionic feature, and the coordination number
of metal V gradually increases with H content. In particular, C2/m-VH8, which consists of
infinite zigzag chains of sole H2 molecules, has the highest
coordination number of 16. From our electron–phonon calculations,
one can see that P63/mmm-VH5 and C2/m-VH8 are superconductors with estimated superconducting temperatures
(Tc) of 18.5 and 71.4 K at 200 GPa, respectively.
Our simulations not only uncovered the crystal structures of V hydrides,
but also established the high-temperature superconductive nature of
them.