High transport critical current densities in textured Fe-sheathed   Sr1-xKxFe2As2+Sn superconducting tapes
  We report the realization of grain alignment in Sn-added Sr1-xKxFe2As2 superconducting tapes prepared by ex-situ powder-in-tube method. At 4.2 K, high transport critical current densities Jc of 2.5x10^4 A/cm^2 (Ic = 180 A) in self-field and 3.5x10^3 A/cm^2 (Ic = 25.5 A) in 10 T have been measured. These values are the highest ever reported so far for Fe-based superconducting wires and tapes. We believe the superior Jc in our tape samples are due to well textured grains and strengthened intergrain coupling achieved by Sn addition. Our results demonstrated an encouraging prospect for application of iron based superconductors. 
Zhaoshun Gao, Lei Wang, Chao Yao, Yanpeng Qi, Chunlei Wang, Xianping   Zhang, Dongliang Wang, Chengduo Wang, Yanwei Ma
cond-mat.supr-con