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arXiv · 1303.3725

Phase diagram and superconductivity at 58.1 K in α-FeAs free SmFeAsO1-xFx

Masaya Fujioka·Saleem James Denholme·Toshinori Ozaki·Hiroyuki Okazaki·Keita Deguchi·Satoshi Demura·Hiroshi Hara·Tohru Watanabe·Hiroyuki Takeya·Takahide Yamaguchi·Hiroaki Kumakura·Yoshihiko Takano
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Abstract

The Phase diagram of SmFeAsO1-xFx in terms of x is exhibited in this study. SmFeAsO1-xFx from x = 0 to x = 0.3 were prepared by low temperature sintering with slow cooling. The low temperature sintering suppresses the formation of the amorphous FeAs, which is inevitably produced as an impurity by using high temperature sintering. Moreover, slow cooling is effective to obtain the high fluorine concentration. The compositional change from feedstock composition is quite small after this synthesis. We can reproducibly observe a record superconducting transition for an iron based superconductor at 58.1 K. This achievement of a high superconducting transition is due to the success in a large amount of fluorine substitution. A shrinking of the a lattice parameter caused by fluorine substitution is observed and the substitutional rate of fluorine changes at x =0.16.

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Masaya Fujioka, Saleem James Denholme, Toshinori Ozaki, Hiroyuki Okazaki, Keita Deguchi, Satoshi Demura, Hiroshi Hara, Tohru Watanabe, Hiroyuki Takeya, Takahide Yamaguchi, Hiroaki Kumakura, Yoshihiko Takano. 2013-07-16. Phase diagram and superconductivity at 58.1 K in α-FeAs free SmFeAsO1-xFx. https://doi.org/10.1088/0953-2048%2F26%2F8%2F085023

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