Growth of (NaxKy)FezSe2 crystals by chlorides flux at low temperatures
  (NaxKy)FezSe2 crystals are prepared by Na, Fe, and Se as starting materials in NaCl/KCl flux at low temperatures~720 {\deg}C. It is found that K is more preferred than Na to enter in between FeSe layers and forms the phase. Thus-obtained crystals contain more superconducting phase in volume fraction and exhibit new features in transport property. Our results provide a promising new synthetic route for preparing quality crystals of iron selenide superconductors. 
Gang Wang, Tianping Ying, Yaobo Huang, Shifeng Jin, Lei Yan, Hong   Ding, Xiaolong Chen
cond-mat.supr-con