(Tl,K,Rb)yFe2-xSe2化合物中的超导电性及与之相关的成分、微结构问题

项目名称： (Tl,K,Rb)yFe2-xSe2化合物中的超导电性及与之相关的成分、微结构问题

项目编号： No.11204059

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 王杭栋

作者单位： 杭州师范大学

项目金额： 30万元

中文摘要： 自2010年底，我们在(Tl,K,Rb)yFe2-xSe2中发现30K超导电性，并提出Fe空位超格子结构以来，针对这类新型Fe基超导体研究，已成为过去一年超导研究领域的热点课题之一，但仍有许多问题有待澄清。本项目将在过去工作的基础上，针对(Tl,K,Rb)yFe2-xSe2化合物中超导电性，及与之相关的成分和微结构问题开展进一步研究，以揭示其本质关联。由于该类化合物化学成份的易变性，该系统超导相总是与反铁磁相共存，我们试图寻找稳定超导相方法，以期获得高纯度的超导相样品；在对现有超导相与反铁磁相共存晶体微结构分析的基础上，揭示其成相规律；合成具有Fe空位超格子结构新型化合物，在保持其超格子结构不变的情况下，通过载流子的引入或外加压强，抑制其长程反铁磁序，揭示该类化合物中存在的新型Block反铁磁序与其超导电性之间的本质关联。通过上述研究，试图加深对该类化合物超导电性和反铁磁序的理解。

中文关键词： 铁硒基超导体；镍硒基超导体；铁空位超格子；重电子行为；多带超导

英文摘要： Since the discovery of superconductivity in the (Tl,K,Rb)yFe2-xSe2, much attention has been paid on these new iron-based superconductors, mostly because of its high critical temperature (Tc ～ 30K, and a Tc onset as high as 40K), and the related Fe vacancy superlattice. However, after a year of research, a lot of issues still remain ambiguous. Based on applicant's previous work, this project will be focused on the study of the superconductivity, and its related composition and microstructure in (Tl,K,Rb)yFe2-xSe2 compounds，expecting to find out their intrinsic relationship. As these compounds are extrem sensitive to the composition, many experiments show the coexistence of the superconductivity and antiferromagnetism. On the basis of analyzing the microstructure, we try to find out the way to control synthesizing process, in order to obtain the stable superconducting phase; We try to synthesize the new compounds with Fe vacancy superlattice, then study the evolution of the superconducting behavior and block antiferromagnetism by introducing carriers or applying pressure. Through this project, we expect to deepen the understanding of the superconductivity and antiferromagnetism in these distinct superconductors.

英文关键词： NiSe-based superconductor；FeSe-based superconductor；iron-vacancy superlattice；heavy electron behavior；multi-band superconductivity