新型铁基超导体材料的研究进展

Recent developments of novel Fe-based superconductors

文章主要介绍了碱金属插层法合成新型铁基超导体的研究进展.通过采用碱金属K对FeSe层状材料插层的方法,得到了一种新型的铁基超导体K0.8Fe1.7Se2,并对该材料的晶体结构与物性进行了研究.结果表明,该化合物的超导转变温度达到30K,这是FeSe体系在常压下的最高超导转变温度.同时,观察到该体系中存在转变温度为43K的超导相,但未得到纯相.通过磁性元素Co的掺杂研究,进一步加深了对K0.8Fe1.7Se2体系超导演化规律的认识.该超导体的发现对深入认识铁基超导体的超导机理,探索具有更高超导转变温度的铁基超导体具有重要意义.

This paper presents recent progress in the study of novel Fe-based superconductors. We report a new Fe-based superconductor K0.8Fe1.7Se2, which was synthesized by intercalating the alkali-metal K into FeSe layers. Its superconducting transition temperature is 30K, which is the highest value at ambient pressure among the FeSe-based materials. Meanwhile, a superconducting phase with a transition temperature of 43K also emerges in this system, but the effort to make a pure sample composed of this 43K phase has not yet been successful. Furthermore, the effect of magnetic Co-doping on the superconductiing behavior is also reported. The results may have important implications for understanding the superconducting mechanism and exploring these new Fe-based superconductors.