Effect of the FeSe Precursor on the Superconductivity of K x Fe2− y Se rong class="a-plus-plus">2 rong>
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- 作者：Ya-jing Cui ; Xiao-feng Wang ; Ping-yuan Li…
- 关键词：K0.8Fe2Se2 ; Superconductivity ; Iron ; based superconductor ; Transport properties ; Magnetic properties
- 刊名：Journal of Superconductivity Incorporating Novel Magnetism
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：29
- 期：11
- 页码：2771-2775
- 全文大小：1,200 KB
- 刊物类别：Physics and Astronomy
- 刊物主题：Physics
Superconductivity, Superfluidity and Quantum Fluids
Magnetism and Magnetic Materials
Condensed Matter
Characterization and Evaluation Materials - 出版者：Springer New York
- ISSN：1557-1947
- 卷排序：29
文摘
Three single crystals of KxFe2−ySe2 with nominal compositions of K0.8Fe2Se2 were prepared by self-flux method in one step or two steps, employing different FeSe precursors as raw materials. Depending on the heat treatment times of FeSe precursors, these three KxFe2−ySe2 crystals are symbolized by KFeSe-0, KFeSe-1, and KFeSe-2, respectively. The onset superconducting transition temperature for KFeSe-1 and KFeSe-2 is around 44 K which is much higher than that of 34.8 K for KFeSe-0. According to the structural and transport properties, it is inferred that the higher-onset transition temperature at 44 K might be derived from another iron-rich KxFe2−ySe2 phase. The employment of FeSe precursors makes it more difficult for K ions to intercalate into FeSe layers, inducing a phase separation and the formation of a second iron-rich phase.