Superconductivity above 12 K with possible multiband features in CsCl-type PbS

Binary metal sulfides are a large material family with distinct physical behavior. Here, we report the super-conductivity observed in PbS by means of pressure engineering. PbS undergoes a series of electronic phase transitions upon compression, and superconductivity occurs above 23.9 GPa in the high-pressure CsCl-type cubic phase. Further compression suppresses the superconductivity while the Tc is reduced from similar to 12.0 K at 23.9 GPa to 6.8 K at 44.3 GPa. Marginally higher Tc approximate to 12.3 K is observed at 19.1 GPa during pressure release. The magnetic field effect verifies the superconductivity with possible multiband features. It is noted that PbS is one of the few binary metal sulfide superconductors with a Tc above 10 K. This work demonstrates that PbS has a high Tc under a moderate pressure due to the chemical "precompression" effect, which is very close to the Tc in pure sulfur at similar to 100 GPa. PbS also shows unexpected multiband behavior in the cubic structure, benefiting the study of pressure-induced superconductivity and the underlying mechanism in metal sulfide compounds.