报告题目:On the way to high temperature superconductors and understanding the mechanism in the FeAs-family 时间: 地点: | |||||
报告人简介:长期从事超导和低温物理研究,在高温超导体磁通动力学,机理问题和非常规超导材料合成和物理性质研究方面获得一批重要成果。目前担任中国科学院物理所研究员,博士生导师, Physica C、 《物理》杂志和Chinese Physics Letters 的编委。1998年获得国家杰出青年基金,2000年获得中国青年科技奖,2004年获得国家自然科学二等奖,2009年获得香港求是集体奖,超导973项目“超导材料科学及应用中的基础问题研究”首席科学家,加拿大国家高等研究计划远东区代表。在 SCI 杂志上发表论文 200 余篇,其中Physical Review Letters 12篇,PNAS 2 篇,Physical Review B 60余篇,写过综述 8 篇,论文引用2000余篇次,在国内外会议上作邀请报告50余次。 | |||||
讲座主要内容:首先,我将介绍合成新型铁砷超导体的发展进程。我们小组首先发现了空穴掺杂型铁砷超导体RE1-xSrxFeAsO (RE=La and Pr),发现并制备出一些列新型母相 化合物 DvFeAsF (Dv=divalent metals: Sr, Ca, Eu etc.) 以及很多超导转变温度Tc 超过50 K 的超导体。同时,我们发明了新型材料(Sr3Sc2O5)Fe2As2 ,(Sr4V2O6)Fe2As2 (V-42622)。V-42622相的超导转变温度大约40 K。这种最新发现的超导材料具有较大的层间距、高各向异性,可能是超导和半金属的多层混合结构。 First of all I will introduce the progress in synthesizing the new superconductors in the FeAs-family. We discovered the first hole doped FeAs-based new superconductors RE1-xSrxFeAsO (RE=La and Pr); discovered and fabricated a series of new parent compounds DvFeAsF (Dv=divalent metals: Sr, Ca, Eu etc.) and many new superconductors with Tc beyond 50 K; invented the new material (Sr3Sc2O5)Fe2As2 with rather large spacing distance between the FeAs planes; found the new superconductor (Sr4V2O6)Fe2As2 (V-42622) with superconducting transition temperature at about 40 K. This latest discovered new superconductor V-42622 exhibits a very high anisotropy and a possible mixture of a superconducting layer and a half-metal. Then I will present some data to show the multi-band superconductivity and give a unified picture on the mechanism of superconductivity in the FeAs-family based on the measurements of lower critical field, point contact tunneling and Hall effect. In collaboration with Gang Mu, Zhaosheng Wang, Huiqian Luo, Huan Yang, Xiyu Zhu, Fei Han, Ying Jia, Bing Zeng, Bing Shen, Cong Ren, Lei Shan |