FeSe-based superconductors with a superconducting transition temperature of 50 K

M Z Shi; N Z Wang; B Lei; J J Ying; C S Zhu; Z L Sun; J H Cui; F B Meng; C Shang; L K Ma; X H Chen

doi:10.1088/1367-2630/aaf312

New Journal of Physics (Jan 2018)

FeSe-based superconductors with a superconducting transition temperature of 50 K

M Z Shi,
N Z Wang,
B Lei,
J J Ying,
C S Zhu,
Z L Sun,
J H Cui,
F B Meng,
C Shang,
L K Ma,
X H Chen

Affiliations

M Z Shi: Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China , Hefei, Anhui 230026, People’s Republic of China
N Z Wang: Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China , Hefei, Anhui 230026, People’s Republic of China
B Lei: Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China , Hefei, Anhui 230026, People’s Republic of China
J J Ying: Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China , Hefei, Anhui 230026, People’s Republic of China
C S Zhu: Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China , Hefei, Anhui 230026, People’s Republic of China
Z L Sun: Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China , Hefei, Anhui 230026, People’s Republic of China
J H Cui: Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China , Hefei, Anhui 230026, People’s Republic of China
F B Meng: Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China , Hefei, Anhui 230026, People’s Republic of China
C Shang: Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China , Hefei, Anhui 230026, People’s Republic of China
L K Ma: Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China , Hefei, Anhui 230026, People’s Republic of China
X H Chen: Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China , Hefei, Anhui 230026, People’s Republic of China; CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai 200050, People’s Republic of China; Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210093, People’s Republic of China

DOI: https://doi.org/10.1088/1367-2630/aaf312
Journal volume & issue: Vol. 20, no. 12
p. 123007

Abstract

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Due to the strong reactivity of alkaline metals and the easy formation of the impurity phase, the superconducting transition temperature ( T _c ) of alkaline metals intercalated FeSe is usually limited to 45 K. To avoid the formation of impurity and improve the T _c , we intercalate a more chemically inert organic ion (rather than the chemically reactive alkaline metals) into FeSe single crystal in this report. A new FeSe-based superconductor, namely (TBA) _0.3 FeSe, with T _c of 50 K, is synthesized by intercalating FeSe single crystal with organic ion tetrabutyl ammonium (TBA ^+ ) via an electrochemical intercalation method, which has the highest T _c among FeSe-based bulk superconductors. The structure of the organic ion intercalated product consists of the alternate stacking of monolayer FeSe and the organic molecule. The superconductivity of (TBA) _0.3 FeSe is confirmed by both the magnetic susceptibility and the transport measurement. It is suggested that the chemically inert organic ion should play a key role in the enhancement of T _c by avoiding the formation of impurity and disorder in FeSe plane as possible. We also suggest that the TBA ^+ intercalated FeSe with well defined shape and higher T _c offer a good playground for further bulk measurement investigation.

Published in New Journal of Physics

ISSN: 1367-2630 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Physics
Website: https://iopscience.iop.org/journal/1367-2630

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