Abstract
We obtained amorphous-FeAs-free SmFeAsO1-xFx using a low temperature sintering with slow cooling. SmFeAsO1-xFx is sintered at 980 °C for 40h and cooled slowly down to 600 °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, 900, 850, 800, 750, and 700 °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.
Original language | English |
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Article number | 094707 |
Journal | Journal of the Physical Society of Japan |
Volume | 82 |
Issue number | 9 |
DOIs | |
Publication status | Published - Sept 2013 |
Externally published | Yes |
Keywords
- Bulk
- Iron-based superconductor
- Low temperature sintering
- Slow cooling
- SmFeAsOF
- Superconductivity