Coexistence of the spin-density wave and superconductivity in Ba1-xKxFe2As2

The relation between the spin-density wave (SDW) and superconducting order is a central topic in the current research on the FeAs-basedhigh-T-C superconductors. Conflicting results exist in the LaFeAs(O,F)-class of materials, for which whether the SDW and superconductivity are mutually exclusive or they can coexist has not been settled. Here we show that for the (Ba, K) Fe2As2 system, the SDW and superconductivity can coexist in an extended range of compositions. The availability of single crystalline samples and high value of the energy gaps would make the materials a model system to investigate the high-T-C ferropnictide superconductivity. Copyright (C) EPLA, 2009