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arXiv · 1507.04823

Superconducting dome and microstructure properties of Rb0.8Fe1.6+xSe2 superconductors

Zhiwei Wang·Zhen Wang·Yao Cai·Zhen Chen·Chao Ma·Huaixin Yang·Jianqi Li
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Abstract

High quality Rb0.8Fe1.6+xSe2 single crystals are grown by a one step melting growth method. Superconductivity has been observed in all samples with x more than 0.05 and the maximum critical temperature Tc~32 K has been obtained in samples with x from 0.1 to 0.2 from electronic resistivity measurement. A superconducting dome in the electronic phase diagram of Tc as a function of Fe content has been observed for the first time in this AxFeySe2 (A=K,Rb) superconducting system. Two coexisting phases with structural modulation vectors of q1=1/5 [3a*+b*] and q2=1/2[a*+b*] have been observed in all superconducting samples by TEM observations. Moreover, phase separation in the superconducting crystals, which can be recognized as micro-stripes in the ab plane, are found to be highly dependent on the Fe content.

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Zhiwei Wang, Zhen Wang, Yao Cai, Zhen Chen, Chao Ma, Huaixin Yang, Jianqi Li. 2015-07-17. Superconducting dome and microstructure properties of Rb0.8Fe1.6+xSe2 superconductors. https://doi.org/10.1088/0953-2048%2F28%2F7%2F075001

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