Superconductivity in oxygen-annealed FeTe 1 − x S x single crystal

We investigated the S-doping-driven phase transition from antiferromagnetic to superconducting in FeTe 1 − x S x single crystals. The partial substitution of Te by S suppresses antiferromagnetism in Fe-square lattice. Superconductivity is induced by oxygen annealing for only FeTe 1 − x S x in which the long-range magnetic ordering is suppressed. To realize superconductivity in FeTe 1 − x S x , both S concentration enough to suppress antiferromagnetism and oxygen annealing are required. Anisotropy of superconductivity in oxygen-annealed FeTe 0.886 S 0.114 was estimated to be 1.17.