Strikingly dissimilar effect of Mn and Zn dopants imposed on local structural distortion of Ba0.5K0.5Fe2As2 superconductor

J Synchrotron Radiat. 2013 May;20(Pt 3):455-9. doi: 10.1107/S0909049513002781. Epub 2013 Mar 1.

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.

Keywords: EXAFS; iron-based superconductor; local structural distortion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Barium Compounds / analysis
  • Barium Compounds / chemistry*
  • Electric Conductivity
  • Manganese / analysis
  • Manganese / chemistry*
  • Materials Testing
  • Molecular Conformation
  • Scattering, Radiation
  • X-Ray Absorption Spectroscopy / methods*
  • X-Rays
  • Zinc / analysis
  • Zinc / chemistry*

Substances

  • Barium Compounds
  • Manganese
  • Zinc