中文摘要：

铁基超导体的发现开启了探索超导材料的新一轮热潮。最新发现的铁基超导体 KxFe2-ySe2有着许多不同寻常的性质。此材料中明显存在相分离，材料中主要的部分是具有反铁磁性质的绝缘相 K2Fe4Se5，超导相只占少量体积。但是超导相在物理上很重要，因为根据理论计算，该材料中不存在空穴型费米面，这样该领域中被广泛接受的S ±配对图像似乎受到挑战。相分离的存在致使此材料中相关研究的难度非常大。该文介绍了此材料中超导相的探索和研究，确认了此材料的超导相是以三维网络状的细丝形态存在，并提出超导的母体相可能是每8个 Fe 位置有一个 Fe 空位形成的8×10这种有序平行四边形结构，称为K2Fe7Se8相。

英文摘要：

The search for new superconducting materials has been spurred on by the discov-ery of iron-based superconductors whose structure and composition is qualitatively different from the cuprates. The study of one such material,KxFe2-ySe2 with a critical temperature of 32 K,is made more difficult by the fact that it separates into two phases- a dominant antiferromagnetic insulating phase K2Fe4Se5,and a minority superconducting phase. In this paper,we identify a three-dimensional net-work of superconducting filaments within this material and present evidence to suggest that the super-conducting phase consists of a single Fe vacancy of every eight Fe-sites arranged in a 8 × 10 paral？lelogram structure.