A series of layered (Sr1−xKx)Fe2As2 compounds with nominal x=0 to 0.40 are synthesized by solid state reaction method. Similar to other parent compounds of iron-based pnictide superconductors, the pure SrFe2As2 shows a strong resistivity anomaly near 210 K, which was ascribed to the spin-density-wave instability. The anomaly temperature is much higher than those observed in LaOFeAs and BaFe2As2, the two prototype parent compounds with ZrCuSiAs- and ThCr2Si2-type structures. K-doping strongly suppresses this anomaly and induces superconductivity. Like in the case of K-doped BaFe2As2, sharp superconducting transitions at Tc∼38 K was observed. We performed the Hall coefficient measurement, and confirmed that the dominant carriers are hole-type. The carrier density is enhanced by a factor of 3 in comparison to F-doped LaOFeAs superconductor.
@article{arxiv.0806.1209,
title = {Superconductivity in hole-doped (Sr$_{1-x}$K$_x$)Fe$_2$As$_2$},
author = {G. F. Chen and Z. Li and G. Li and W. Z. Hu and J. Dong and X. D. Zhang and P. Zheng and N. L. Wang and J. L. Luo},
journal= {arXiv preprint arXiv:0806.1209},
year = {2008}
}