1111.6472 (Y. Kawasaki et al.)

Phase diagram and oxygen annealing effect of FeTe1-xSex iron-based
superconductor    [PDF]

Y. Kawasaki, K. Deguchi, S. Demura, T. Watanabe, H. Okazaki, T. Ozaki, T. Yamaguchi, H. Takeya, Y. Takano

Phase diagrams of as-grown and O2-annealed FeTe1-xSex determined from magnetic susceptibility measurement were obtained. For as-grown samples, the antiferromagnetic order was fully suppressed in the range region x \geq 0.15, and weak superconductivity appeared when x \geq 0.1. Beginning at x = 0.5, weak superconductivity was found to evolve into bulk superconductivity. Interestingly, for O2-annealed samples, complete suppression of magnetic order and the occurrence of bulk superconductivity were observed when x \geq 0.1. We found that O2-annealing induces bulk superconductivity for FeTe1-xSex. Oxygen probably plays a key role in the suppression of the magnetic order and the appearance of bulk superconductivity.

View original: http://arxiv.org/abs/1111.6472