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arXiv 1202.4340cond-mat.supr-con
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AxFe2Se2(A = Li,Na,Ba,Sr,Ca,Yb,Eu)在30 K~46 K的超导电性观察

Observation of superconductivity at 30 K~46 K in AxFe2Se2 (A = Li, Na, Ba, Sr, Ca, Yb, and Eu)

T. P. Ying, X. L. Chen, G. Wang, S. F. Jin, T. T. Zhou, X. F. Lai, H. Zhang, W. Y. Wang

摘要:

自从在KFe 2Se 2中发现约30 K的超导性以来,人们一直在寻求通过使用高温路线插入较小尺寸的碱金属(Li,Na)和碱土金属的新的硒化铁超导体,但迄今为止都失败了。本文证明了在室温下用氨化法在FeSe层间插入Li、Na、Ba、Sr、Ca、Yb和Eu等金属,可以得到一系列Tc提高到30~46 K的超导体。对它们的粉末X射线衍射图谱的分析表明,所有的主相都可以基于体心四元点阵进行索引,a~3.755-3.831 nm,c~15.99-20.54 nm。电阻率显示相应的急剧转变,在45 K和39 K的NaFe 2Se 2和Ba0.8Fe2Se2,分别确认其体超导性。这些发现为研究这些超导体的性质提供了一个新的起点,也为探索新的超导体提供了一条有效的合成路线。

英文摘要:

New iron selenide superconductors by intercalating smaller-sized alkali metals (Li, Na) and alkaline earths using high-temperature routes have been pursued ever since the discovery of superconductivity at about 30 K in KFe2Se2, but all have failed so far. Here we demonstrate that a series of superconductors with enhanced Tc=30~46 K can be obtained by intercalating metals, Li, Na, Ba, Sr, Ca, Yb, and Eu in between FeSe layers by the ammonothermal method at room temperature. Analysis on their powder X-ray diffraction patterns reveals that all the main phases can be indexed based on body-centered tetragonal lattices with a~3.755-3.831 Å while c~15.99-20.54 Å. Resistivities show the corresponding sharp transitions at 45 K and 39 K for NaFe2Se2 and Ba0.8Fe2Se2, respectively, confirming their bulk superconductivity. These findings provide a new starting point for studying the properties of these superconductors and an effective synthetic route for the exploration of new superconductors as well.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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