Pressure-Induced Enhancement of Superconductivity and Structural Transition in BiS2-Layered LaO1−xFxBiS2

This is the authors' abstract. We don't add key points for this paper.

The newly discovered BiS₂-based LaO₁₋ₓFₓBiS₂ (x=0.5) becomes superconductive at Tc=2.5 K. Electrical resistivity and magnetization measurements are performed under pressure to determine the pressure dependence of the superconducting transition temperature Tc. We observe that Tc abruptly increases from 2.5 K to 10.7 K at a pressure of 0.7 GPa. According to high-pressure X-ray diffraction measurements, a structural phase transition from a tetragonal phase (P4/$nmm$) to a monoclinic phase (P2₁/m) also occurs at around ~ 1 GPa. We consider that a pressure-induced enhancement of superconductivity is caused by the structural phase transition.