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arXiv · 1303.1309

{\alpha}-FeAs-free SmFeAsO1-xFx by low temperature sintering with slow cooling

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

We obtained amorphous-FeAs-free SmFeAsO1-xFx using a low temperature sintering with slow cooling. SmFeAsO1-xFx is sintered at 980 {\deg}C for 40 hours and cooled slowly down to 600 {\deg}C. The low temperature sintering suppresses the formation of amorphous FeAs, and the slow cooling introduces much fluorine into SmFeAsO1-xFx. The superconductivity of this sample appears at 57.8 K and the superconducting volume fraction reaches 96 %. To study the change of fluorine concentration during the cooling process, samples are quenched by water at 950 {\deg}C, 900 {\deg}C, 850 {\deg}C, 800 {\deg}C, 750 {\deg}C and 700 {\deg}C. It is found that fluorine is substituted not only at the maximum heating temperature but also during the cooling process. The low temperature sintering with slow cooling is very effective to obtain a homogeneous SmFeAsO1-xFx with high fluorine concentration.

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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. 2013-03-06. {\alpha}-FeAs-free SmFeAsO1-xFx by low temperature sintering with slow cooling. https://doi.org/10.7566/jpsj.82.094707

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