Coexistence of superconductivity and antiferromagentic order in Er_(2)O_(2)Bi with anti-ThCr_(2)Si_(2) structure  

作　　者：Lei Qiao Ning-hua Wu Tianhao Li Siqi Wu Zhuyi Zhang Miaocong Li Jiang Ma Baijiang Lv Yupeng Li Chenchao Xu Qian Tao Chao Cao Guang-Han Cao Zhu-An Xu 

机构地区：[1]Zhejiang Province Key Laboratory of Quantum Technology and Device,Department of Physics,Zhejiang University,Hangzhou 310027,China [2]Key Laboratory of Neutron Physics and Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang 621999,China [3]Department of Physics,Hangzhou Normal University,Hangzhou 310036,China [4]State Key Laboratory of Silicon Materials,Zhejiang University,Hangzhou 310027,China

出　　处：《Frontiers of physics》2021年第6期133-141,共9页物理学前沿（英文版）

基　　金：This work was supported by the National Key R&D Projects of China(Grant Nos.2019YFA0308602 and 2016YFA0300402);the National Natural Science Foundation of China(Grant No.11774305);the Fundamental Research Funds for the Central Universities of China.

摘　　要：We investigated the coexistence of superconductivity and antiferromagnetic order in the compound Er_(2)O_(2)Bi with anti-ThCr_(2)Si_(2)-type structure through resistivity,magnetization,specific heat measurements and first-principle calculations.The superconducting transition temperature Tc of 1.23 K and antiferromagnetic transition temperature TN of 3 K are observed in the sample with the best nominal composition.The superconducting upper critical field H_(c2)(0)and electron-phonon coupling constantλe−ph in Er_(2)O_(2)Bi are similar to those in the previously reported non-magnetic superconductor Y_(2)O_(2)Bi with the same structure,indicating that the superconductivity in Er_(2)O_(2)Bi may have the same origin as in Y_(2)O_(2)Bi.The first-principle calculations of Er_(2)O_(2)Bi show that the Fermi surface is mainly composed of the Bi 6p orbitals both in the paramagnetic and antiferromagnetic state,implying minor effect of the 4f electrons on the Fermi surface.Besides,upon increasing the oxygen incorporation in Er_(2)O_(x)Bi,Tc increases from 1 to 1.23 K and TN decreases slightly from 3 K to 2.96 K,revealing that superconductivity and antiferromagnetic order may compete with each other.The Hall effect measurements indicate that hole-type carrier density indeed increases with increasing oxygen content,which may account for the variations of Tc and TN with different oxygen content.

关 键 词：SUPERCONDUCTIVITY Kondo lattice magnetic correlation phase diagram 

分 类 号：O47[理学—半导体物理]