Critical current density properties in polycrystalline Sr0.6K0.4Fe2As2 superconductors

The recent discovery of superconductivity in iron arsenide compounds REFeAsO (RE = rare earth) or AFe 2 As 2 (A = alkaline earth) has attracted great attention due to the high T c that raised above 50 K. In this study, the effect of Ag addition (20 wt.%) on the critical current density J c of polycrystalline Sr 0.6 K 0.4 Fe 2 As 2 was investigated for improvement of the weak links in polycrystalline iron-based superconductors. Although effect of Ag addition on the intra-grain current density J c local was not confirmed, the connectivity among grains is speculated to be improved by filling voids among grains by Ag.