Superconductivity induced by La doping in Sr1-xLaxFBiS2

Through a combination of x-ray diffraction, electrical transport, magnetic susceptibility, and heat-capacity measurements, we report the effect of La doping on Sr in the newly discovered SrFBiS2 system. Superconducting transition with critical temperature T-c of 2.8 K, developed from a semiconducting-like normal state, was found in Sr0.5La0.5FBiS2. A strong diamagnetic signal and a clear specific-heat anomaly associated with this transition were observed, confirming bulk superconductivity. The upper critical field H-c2(0) was estimated to be 1 T by using the Ginzburg-Landau approach. Our experiments therefore demonstrate that bulk superconductivity can be achieved by electron doping in the SrFBiS2 system. DOI: 10.1103/PhysRevB.87.020504