Evolution of superconductivity in LaO1-xFxBiS2 prepared by high pressure   technique
  Novel BiS2-based superconductors LaO1-xFxBiS2 prepared by the high pressure synthesis technique were systematically studied. It was found that the high pressure annealing strongly 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. 
K. Deguchi, Y. Mizuguchi, S. Demura, H. Hara, T. Watanabe, S. J.   Denholme, M. Fujioka, H. Okazaki, T. Ozaki, H. Takeya, T....
cond-mat.supr-con