摘要
We have synthesized two iron fluo-arsenides ACa2Fe4As4Fz with A = Rb and Cs, analogous to the newly discovered superconductor KCazFe4As4F2. The quinary inor- ganic compounds crystallize in a body-centered tetragonal lattice with space group I4/mmm, which contain double Fe2As2 layers that are separated by insulating Ca2F2 layers. The electrical and magnetic measurements on the polycrys- talline samples demonstrate that the new materials undergo superconducting transitions at Tc = 30.5 and 28.2 K, respec- tively, without extrinsic doping. The correlations between Tc and structural parameters are discussed.
本文合成了与新发现的KCa_2Fe_4As_4F_2超导体结构相同的两种铁砷氟化物ACa_2Fe_4As_4F_2(A=Rb,Cs).该五元无机物具有四方体心晶格,空间群为I4/mmm,包含被Ca_2F_2绝缘层分开的双Fe_2As_2层.对多晶样品的电阻和直流磁化率的测量表明,ACa_2Fe_4As_4F_2(A=Rb,Cs)样品无需外在掺杂即呈现出30.5和28.2K的超导电性.文中还讨论了其T_c与晶体结构参数间的关联.
作者
Zhicheng Wang
王志成;何朝阳;汤章图;武思祺;曹光旱(Department of Physics and Stat Key Lab of Silicon Materials, Zhejiang University, Hangzhou 310027, China Collaborative Innovation Centre of Advanced Microstructures, Nanjing 210093, China)
基金
supported by the National Natural Science Foundation of China(90922002 and 11190023)
the National Key Research and Development Program of China(2016YFA0300202)
