High-temperature superconductivity in the Ti-H system at high pressures
Abstract
Search for stable high-pressure compounds in the Ti-H system reveals the existence of titanium hydrides with new stoichiometries, including I b a m -Ti2H5 , I 4 /m -Ti5H13 , I 4 ¯-Ti5H14 , F d d d -TiH4 , I m m m -Ti2H13 , P 1 ¯-TiH12 , and C 2 /m -TiH22 . Our calculations predict I 4 /m m m →R 3 ¯m and I 4 /m m m → C m m a transitions in TiH and TiH2, respectively. Phonons and the electron-phonon coupling in all searched titanium hydrides are analyzed at high pressure. It is found that I m m m -Ti2H13 , rather than the hydrogen-richest C 2 /m -TiH22 , exhibits the highest superconducting critical temperature Tc. The estimated Tc of I m m m -Ti2H13 and C 2 /m -TiH22 are, respectively, 127.4-149.4 K (μ*=0.1 -0.15) at 350 GPa and 91.3-110.2 K at 250 GPa, as found by numerically solving the Eliashberg equations.
- Publication:
-
Physical Review B
- Pub Date:
- April 2020
- DOI:
- 10.1103/PhysRevB.101.134108
- arXiv:
- arXiv:1911.09293
- Bibcode:
- 2020PhRvB.101m4108Z
- Keywords:
-
- Condensed Matter - Materials Science;
- Condensed Matter - Superconductivity
- E-Print:
- doi:10.1103/PhysRevB.101.134108