Superconductivity in KCa2Fe4As4F2 with Separate Double Fe2As2 Layers.
We report the synthesis, crystal structure, and physical properties of a quinary iron arsenide fluoride, KCa2Fe4As4F2. The new compound crystallizes in a body-centered tetragonal lattice (space group I4/mmm, a = 3.8684(2) Å, c = 31.007(1) Å, Z = 2) that contains double Fe2As2 conducting layers separated by insulating Ca2F2 layers. Our measurements of electrical resistivity, direct-current magnetic susceptibility, and heat capacity demonstrate bulk superconductivity at 33 K in KCa2Fe4As4F2.
Department of Physics and State Key Lab of Silicon Materials, Zhejiang University , Hangzhou 310027, China.
Zhi-Cheng
ZC
Wang
Department of Physics and State Key Lab of Silicon Materials, Zhejiang University , Hangzhou 310027, China.
Chao-Yang
CY
He
Department of Physics and State Key Lab of Silicon Materials, Zhejiang University , Hangzhou 310027, China.
Si-Qi
SQ
Wu
Department of Physics and State Key Lab of Silicon Materials, Zhejiang University , Hangzhou 310027, China.
Zhang-Tu
ZT
Tang
Department of Physics and State Key Lab of Silicon Materials, Zhejiang University , Hangzhou 310027, China.
Yi
Y
Liu
Department of Physics and State Key Lab of Silicon Materials, Zhejiang University , Hangzhou 310027, China.
Abduweli
A
Ablimit
Department of Physics and State Key Lab of Silicon Materials, Zhejiang University , Hangzhou 310027, China.
Chun-Mu
CM
Feng
Department of Physics and State Key Lab of Silicon Materials, Zhejiang University , Hangzhou 310027, China.|Collaborative Innovation Centre of Advanced Microstructures , Nanjing 210093, China.
Guang-Han
GH
Cao