混合溶剂调控插层FeSe基超导体的层间距  

Tuning the interlayer spacing in intercalated FeSe-based superconductors through mixed solvent

作　　者：胡国兵 石孟竹 孟凡保 江风云 高敏 钟钒 陈欢 郭景锋 罗习刚 Guobing Hu;Mengzhu Shi;Fanbao Meng;Fengyun Jiang;Min Gao;Fan Zhong;Huan Chen;Jingfeng Guo;Xigang Luo(Physical Science and Technology College,Yichun University,Yichun 336000,China;Key Laboratory of Strongly Coupled Quantum Matter Physics,Chinese Academy of Sciences,Hefei National Laboratory for Physical Sciences at Microscale,and Department of Physics,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]Physical Science and Technology College,Yichun University,Yichun 336000,China [2]Key Laboratory of Strongly Coupled Quantum Matter Physics,Chinese Academy of Sciences,Hefei National Laboratory for Physical Sciences at Microscale,and Department of Physics,University of Science and Technology of China,Hefei 230026,China

出　　处：《Science China Materials》2024年第1期295-300,共6页中国科学（材料科学）（英文版）

基　　金：supported by the National Natural Science Foundation of China (12264052);the Science and Technology Research Project of Jiangxi Provincial Department of Education (GJJ211607)。

摘　　要：近年来,通过湿化学方法探索合成新型插层FeSe基超导体一直是凝聚态物理的研究热点之一.本文中,我们利用溶剂热离子交换技术成功合成出两种FeSe衍生物:c轴晶胞参数为9.93Å的Li_(0.34)Se_(0.05)(EG)_(0.14)-FeSe和c轴晶胞参数为13.85Å的Li_(0.21)Se_(0.05)(EG)_(0.26)FeSe.通过调整反应溶剂可以调控以上两种FeSe衍生物的层间距.磁化率和电阻率测试表明它们的超导转变温度(Tc)均为30 K左右,似乎与FeSe层层间距的大小无关.与原始FeSe单晶相比,X射线光电子能谱结果显示FeSe层Fe的价态降低,这表明Tc的提高可能是由于电子掺杂效应引起的.我们的研究为探索合成插层铁基超导体提供了有价值的参考,并为在超导领域探索新型插层材料提供了新的可能性.Recently,the exploration of novel intercalated FeSe-based superconductors through the wet chemical reac-tions has been a focal point in condensed matter physics.Here,we present the successful synthesis of two FeSe derivatives,namely Li_(0.34)Se_(0.05)(EG)_(0.14)FeSe and Li_(0.21)Se_(0.05)(EG)_(0.26)FeSe,whose c-axis lattice parameters are 9.93Åand 13.85Å,re-spectively,using the solvothermal ion-exchange technique.The interlayer spacing of the two FeSe derivatives can be tuned by the change of mixed solvent during the synthesis process.The resistivity and magnetic susceptibility measurement re-sults show that their superconducting transition temperatures(Tc)are both about 30 K.Interestingly,the Tc values are found to be independent of the interlayer spacing of the FeSe layer.Compared with the pristine FeSe single crystal,X-ray photo-electron spectroscopy results display a decrease of the Fe va-lence,indicating that the enhancement in Tc may be caused by an electron doping effect.Our research provides valuable in-sights into the intercalation of FeSe-based superconductors and offers new possibilities for exploring novel intercalated materials within the field of superconductivity.

关 键 词：超导转变温度 凝聚态物理 X射线光电子能谱 铁基超导体 混合溶剂 离子交换技术 湿化学方法 反应溶剂 

分 类 号：O511.3[一般工业技术—材料科学与工程]