Superconductivity in Sm-doped CaFe2As2 single crystals  

作　　者：陈东云 阮彬彬 于佳 郭琦 王小川 穆青隔 潘伯津 刘通 陈根富 任治安 

机构地区：[1]Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China [2]Collaborative Innovation Center of Quantum Matter, Beijing 100190, China

出　　处：《Chinese Physics B》2016年第6期59-62,共4页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.11474339);the National Basic Research Program of China(Grant Nos.2010CB923000 and 2011CBA00100);the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB07020100)

摘　　要：In this article,the Sm-doping single crystals Ca1-xSmxFe2As2（x = 0 0.2） were prepared by the Ca As flux method,and followed by a rapid quenching treatment after the high temperature growth.The samples were characterized by structural,resistive,and magnetic measurements.The successful Sm-substitution was revealed by the reduction of the lattice parameter c,due to the smaller ionic radius of Sm3＋than Ca2＋.Superconductivity was observed in all samples with onset Tc varying from 27 K to 44 K upon Sm-doping.The coexistence of a collapsed phase transition and the superconducting transition was found for the lower Sm-doping samples.Zero resistivity and substantial superconducting volume fraction only happen in higher Sm-doping crystals with the nominal x 〉 0.10.The doping dependences of the c-axis length and onset Tc were summarized.The high-Tc observed in these quenched crystals may be attributed to simultaneous tuning of electron carriers doping and strain effect caused by lattice reduction of Sm-substitution.In this article,the Sm-doping single crystals Ca1-xSmxFe2As2（x = 0 0.2） were prepared by the Ca As flux method,and followed by a rapid quenching treatment after the high temperature growth.The samples were characterized by structural,resistive,and magnetic measurements.The successful Sm-substitution was revealed by the reduction of the lattice parameter c,due to the smaller ionic radius of Sm3＋than Ca2＋.Superconductivity was observed in all samples with onset Tc varying from 27 K to 44 K upon Sm-doping.The coexistence of a collapsed phase transition and the superconducting transition was found for the lower Sm-doping samples.Zero resistivity and substantial superconducting volume fraction only happen in higher Sm-doping crystals with the nominal x 〉 0.10.The doping dependences of the c-axis length and onset Tc were summarized.The high-Tc observed in these quenched crystals may be attributed to simultaneous tuning of electron carriers doping and strain effect caused by lattice reduction of Sm-substitution.

关 键 词：SUPERCONDUCTIVITY Sm-doping CaFe2As2 collapsed structure 

分 类 号：O511.3[一般工业技术—材料科学与工程]