1144型铁基超导材料的研究现状及展望  

1144-type iron-based superconducting materials:Status and prospect

作　　者：成者 张现平[1,3] 董持衡 马衍伟 Zhe Cheng;Xianping Zhang;Chiheng Dong;Yanwei Ma(Key Laboratory of Applied Superconductivity,Institute of Electrical Engineering,Chinese Academy of Sciences,Beijing 100190,China;Department of Physics,Nanchang University,Nanchang 330031,China;School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049.China)

机构地区：[1]中国科学院电工研究所应用超导重点实验室,北京100190 [2]南昌大学理学院,南昌330031 [3]中国科学院大学工程科学学院,北京100049

出　　处：《科学通报》2022年第8期758-769,共12页Chinese Science Bulletin

基　　金：国家自然科学基金(51861135311,U1832213,51721005);国家重点研发计划(2018YAF0704200,2017YFE0129500);中国科学院战略性先导科技专项(XDB25000000)和中国科学院前沿科学重点研究项目(QYZDJ-SSW-JSC026)资助。

摘　　要：以122型为代表的铁基超导体在临界电流密度、上临界场以及各向异性方面具有较大的优势,引发了新一轮研究热潮.目前,虽然122型线带材的性能已达到实用化水平,但该体系仍存超导相非均匀分布等问题,限制了其载流性能的提升.新发现的具有化学计量比的1144型超导材料具有更好的均匀性、独特的钉扎特性以及更高的载流性能,使其适合于高场应用.本文简述了1144材料的结构和超导特性,并详细分析了单晶、多晶及超导线带材制备工艺的优化,以及性能提升的方法.同时,为提高1144型铁基超导线带材的临界电流密度,讨论了改善晶粒连接性和超导相纯度的途径.The 122-type iron-based superconductor(IBSC)has great advantages in critical current density(J_(c)),upper critical field(H_(c2)),and anisotropy,which has prompted a new interest in applied research.Although the J_(c) performance of 122-type wires and tapes has broken through the practical level,this system still has disadvantages,such as the non-uniform distribution of the superconducting phase,which limits the enhancement of its transport properties.The recently discovered stoichiometric 1144-type IBSC material has a more uniform distribution of the K atoms.As one of the 1144-type IBSCmaterials,Ca KFe_(4)As_(4) not only has a high superconducting transition temperature(T_(c))and H_(c2) similar to the 122-type IBSCbut also has an extremely large J_(c)(~10^(7)A/cm^(2)at 5 K and self-field),which has been confirmed by multiple research groups.Besides,unique pinning characteristics,such as the weak field dependence of the J_(c) and the second peak effect of the J_(c)^(//c)-T curve,have been observed in Ca KFe_(4)As_(4) single crystals,indicating their great potential for high-field applications.This review briefly describes the structure and superconducting properties of 1144-type IBSC materials,comparing them with those of other IBSC materials while focusing on the optimization of the fabrication process and J_(c) improvement of single crystals,polycrystals,and superconducting wires and tapes.So far,the process of preparing large-size and highquality Ca KFe_(4)As_(4)single crystals has been mature.The J_(c) of single crystals can be increased up to five times via irradiation or Ni/Co doping.Among the various methods of preparing Ca KFe_(4)As_(4) polycrystals,the J_(c) of polycrystals prepared via the SPS method is the highest,which is 8×10^(4)A/cm^(2)(4.2 K and self-field).In addition,high-performance Ca KFe_(4)As_(4)tapes have been successfully fabricated,with T_(c)~33 K,the upper critical fieldμH_(c2)>100 T,and anisotropicγ~2.Its J_(c) reaches2.2×10^(4)A/cm^(2)at 4.2 K and 10 T,indicating that the preliminary

关 键 词：1144型铁基超导体 单晶 线带材 辐照 临界电流密度 

分 类 号：TM26[一般工业技术—材料科学与工程]