Decoupling of Rattling Mode and Superconductivity in Filled-Skutterudite Ba_(x)Ir_(4)Sb_(12)  

作　　者：刘辉 于同旭 张志华 应天平 Hui Liu;Tongxu Yu;Zhihua Zhang;Tianping Ying(School of Materials Science and Engineering,Dalian Jiaotong University,Dalian 116028,China;Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Chinese Academy of Sciences,Beijing 100190,China;Suzhou Laboratory,Suzhou 215123,China)

机构地区：[1]School of Materials Science and Engineering,Dalian Jiaotong University,Dalian 116028,China [2]Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [3]University of Chinese Academy of Sciences,Chinese Academy of Sciences,Beijing 100190,China [4]Suzhou Laboratory,Suzhou 215123,China

出　　处：《Chinese Physics Letters》2024年第7期132-139,共8页中国物理快报（英文版）

基　　金：supported by Beijing Natural Science Foundation (Grant No.Z200005);the National Key Research and Development Program of China (Grant No.2021YFA1401800);the National Natural Science Foundation of China (Grant Nos.52272267 and 52202342)。

摘　　要：The rattling mode,an anharmonic vibrational phonon,is widely recognized as a critical factor in the emergence of superconductivity in caged materials.Here,we present a counterexample in a filled-skutterudite superconductor Ba_(x)Ir_(4)Sb_(12)(x=0.8,0.9,1.0),synthesized via a high-pressure route.Transport measurements down to liquid 3He temperatures reveal a transition temperature(T_(c))of 1.2 K and an upper critical field(H_(c2))of 1.3 T.Unlike other superconductors with caged structures,the Ba_(x)Ir_(4)Sb_(12)(X=P,As,Sb)family exhibits a monotonic decreasing T_(c) with the enhancement of the rattling mode,as indicated by fitting the Bloch–Grüneisen formula.Theoretical analysis suggests that electron doping from Ba transforms the direct bandgap IrSb3 into a metal,with the Fermi surface dominated by the hybridization of Ir 5d and Sb 5p orbitals.Our findings of decoupled rattling modes and superconductivity distinguish the Ba_(x)Ir_(4)Sb_(12) family from other caged superconductors,warranting further exploration into the underlying mechanism.

关 键 词：mechanism materials SUPERCONDUCTIVITY 

分 类 号：O469[理学—凝聚态物理]