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arXiv · 1711.05440

Revisiting the electron-doped SmFeAsO: enhanced superconductivity up to 58.6 K by Th and F codoping

Xiao-Chuan Wang·Jia Yu·Bin-Bin Ruan·Bo-Jin Pan·Qing-Ge Mu·Tong Liu·Kang Zhao·Gen-Fu Chen·Zhi-An Ren
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Abstract

In the iron-based high-Tc bulk superconductors, Tc above 50K was only observed in the electron-doped 1111-type compounds. Here we revisit the electron-doped SmFeAsO polycrystals to make a further investigation for the highest T-c in these materials. To introduce more electron carriers and less crystal lattice distortions, we study the Th and F codoping effects into the Sm-O layers with heavy electron doping. Dozens of Sm1-x Th-x FeAsO1-y F-y samples are synthesized through the solid state reaction method, and these samples are carefully characterized by the structural, resistive, and magnetic measurements. We find that the codoping of Th and F clearly enhances the superconducting T-c more than the Th or F single-doped samples, with the highest record T-c up to 58.6K when x= 0.2 and y= 0.225. Further element doping causes more impurities and lattice distortions in the samples with a weakened superconductivity.

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Xiao-Chuan Wang, Jia Yu, Bin-Bin Ruan, Bo-Jin Pan, Qing-Ge Mu, Tong Liu, Kang Zhao, Gen-Fu Chen, Zhi-An Ren. 2017-11-15. Revisiting the electron-doped SmFeAsO: enhanced superconductivity up to 58.6 K by Th and F codoping. https://doi.org/10.1088/0256-307x%2F34%2F7%2F077401

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