Regensburg 2016 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 62: Focus Session: High Temperature Superconductivity in Hydrides
TT 62.6: Hauptvortrag
Donnerstag, 10. März 2016, 12:15–12:45, H20
New sulfur hydride H3S and excellent superconductivity at high — •Tian Cui — State Key Laboratory of Superhard Materials, College of physics, Jilin University, Changchun, P. R. China
It is predicted theoretically that molecular hydrogen would dissociate into an atomic phase with metallic properties at high pressures. Metallic hydrogen is believed to be a room-temperature superconductor. However, metallization of hydrogen is still debates in laboratory. As an alternative, hydrogen-rich compounds are extensively explored since their metallization can happen at relatively lower pressures by means of chemical pre-compressions. Here, a new sulfur hydride H3S that hardly occur at atmospheric pressure was predicted to be formed at high pressure by two main ways. We also found two intriguing metallic structures with R3m and Im-3m symmetries above 111 GPa and 180 GPa, respectively. Remarkably, the estimated Tc of Im-3m phase at 200 GPa achieves a very high value of 191-204 K, reaching an order of 200 K. Further calculation shown that the H atoms play a significant role in superconductivity. The experimental discovery of superconductivity with a high Tc = 203 K in H-S system at high pressure has verified our theoretically predicted results. Furthermore, the predicted R3m and Im-3m structures have been recently confirmed experimentally by synchrotron XRD.