title: Strikingly dissimilar effect of Mn and Zn dopants imposed on local structural distortion of Ba0.5K0.5Fe2As2 superconductor.
abstract: To clarify the contrasting impurity effects of Mn and Zn dopants on the critical temperature of optimally doped Ba0.5K0.5Fe2As2 superconductors, extended X-ray absorption fine-structure spectroscopy was implemented at the Fe and As K-edge. In Mn-doped compounds a gradual deviation of the symmetric FeAs4 tetrahedron and weakening of the Fe-As bond was observed. Conversely, in Zn-doped compounds the perfect FeAs4 tetrahedron is maintained and the Fe-As bond is rigid. The local structural details are consistent with the development of superconductivity in these two systems, suggesting a significant role played by the topology of the FeAs4 tetrahedron and rigidness of the Fe-As bond in Mn/Zn-doped Ba0.5K0.5Fe2As2 superconductors.
authors.affiliation: College of Science, Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Cheng
authors.forename: Peng
authors.initials: P
authors.lastname: Dong
authors.forename: Wangsheng
authors.initials: W
authors.lastname: Chu
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Haihu
authors.initials: H
authors.lastname: Wen
authors.forename: Augusto
authors.initials: A
authors.lastname: Marcelli
authors.forename: Ziyu
authors.initials: Z
authors.lastname: Wu
mesh_terms: D017609:Barium Compounds / Q000032:analysis / Q000737:chemistry*; D004553:Electric Conductivity; D008345:Manganese / Q000032:analysis / Q000737:chemistry*; D008422:Materials Testing; D008968:Molecular Conformation; D012542:Scattering, Radiation; D056928:X-Ray Absorption Spectroscopy / Q000379:methods*; D014965:X-Rays; D015032:Zinc / Q000032:analysis / Q000737:chemistry*
chemical_list: D017609:Barium Compounds; D008345:Manganese; D015032:Zinc
keywords: EXAFS; iron-based superconductor; local structural distortion