First principles study of the superconductivity in Os-S system

Abstract

Abstract Due to the spin-orbital coupling effects of the Os-5d electrons, we performed structure searches on the possible superconductivity in the Os-S system. We predict a series of novel structures in the Os-S system, including Pmn21, I-4m2, P63mc, I4mm, R3m, P6/mmm. I-4m2 phase is a potential superconductor of 3.6 K at 0 GPa. The superconductivity is associated with the soft phonon modes of Os. Interestingly, with the increase of pressure, the soft phonon mode near the M/X points will start moving up to a higher position. There is no superconducting transition temperature in the I-4m2 phase when the pressure reaches 50 GPa.