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arXiv · 1704.01051

Crystal Structure and Superconductivity at about 30 K in $A$Ca$_2$Fe$_4$As$_4$F$_2$ ($A$ = Rb, Cs)

Zhi-Cheng Wang·Chao-Yang He·Zhang-Tu Tang·Si-Qi Wu·Guang-Han Cao
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Abstract

We have synthesized two iron fluo-arsenides $A$Ca$_2$Fe$_4$As$_4$F$_2$ with $A$ = Rb and Cs, analogous to the newly discovered superconductor KCa$_2$Fe$_4$As$_4$F$_2$. The quinary inorganic compounds crystallize in a body-centered tetragonal lattice with space group I4/mmm, which contain double Fe$_2$As$_2$ layers that are separated by insulating Ca$_2$F$_2$ layers. Our electrical and magnetic measurements on the polycrystalline samples demonstrate that the new materials undergo superconducting transitions at Tc = 30.5 K and 28.2 K, respectively, without extrinsic doping. The correlations between Tc and structural parameters are discussed.

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Zhi-Cheng Wang, Chao-Yang He, Zhang-Tu Tang, Si-Qi Wu, Guang-Han Cao. 2017-04-04. Crystal Structure and Superconductivity at about 30 K in $A$Ca$_2$Fe$_4$As$_4$F$_2$ ($A$ = Rb, Cs). https://doi.org/10.1007/s40843-016-5150-x

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