Evolution of superconductivity in LaO1−xFxBiS2 prepared by high-pressure technique

Abstract

Novel BiS2-based superconductors LaO1−xFxBiS2 prepared by a high-pressure synthesis technique were systematically studied. It was found that the high-pressure annealing strongly shrank the lattice as compared to the LaO1−xFxBiS2 samples prepared by conventional solid-state reaction at ambient pressure. Bulk superconductivity was observed within a wide F concentration range of x = 0.2–0.7. On the basis of those results, we have established a phase diagram of LaO1−xFxBiS2.