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arXiv · 1903.04822

Single-crystal growth and extremely high H_c2 of 12442-type Fe-based superconductor KCa_2Fe_4As_4F_2

Teng Wang·Jianan Chu·Hua Jin·Jiaxin Feng·Lingling Wang·Yekai Song·Chi Zhang·Wei Li·Zhuojun Li·Tao Hu·Da Jiang·Wei Peng·Xiaosong Liu·Gang Mu
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Abstract

Millimeter sized single crystals of KCa_2Fe_4As_4F_2 were grown using a self-flux method. The chemical compositions and crystal structure were characterized carefully. Superconductivity with the critical transition T_c = 33.5 K was confirmed by both the resistivity and magnetic susceptibility measurements. Moreover, the upper critical field H_c2 was studied by the resistivity measurements under different magnetic fields. A rather steep increase for the in-plane H_c2^ab with cooling, dμ_0H_c2^a/dT|T_c = -50.9 T/K, was observed, indicating an extremely high upper critical field. Possible origins for this behavior were discussed. The findings in our work is a great promotion both for understanding the physical properties and applications of 12442-type Fe-based superconductors.

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Teng Wang, Jianan Chu, Hua Jin, Jiaxin Feng, Lingling Wang, Yekai Song, Chi Zhang, Wei Li, Zhuojun Li, Tao Hu, Da Jiang, Wei Peng, Xiaosong Liu, Gang Mu. 2019-03-12. Single-crystal growth and extremely high H_c2 of 12442-type Fe-based superconductor KCa_2Fe_4As_4F_2. https://doi.org/10.1021/acs.jpcc.9b04624

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