MOD-REBCO高温超导涂层导体的人工磁通钉扎及其调制进展  

Advances in artificial flux pinning of MOD-REBCO superconducting coated conductors

作　　者：黄荣铁 陈静 刘志勇[1,2] 李勇 菅洪彬 豆文芝 张宁 周迪帆 彭思思[1,3] 蔡传兵 HUANG RongTie;CHEN Jing;LIU ZhiYong;LI Yong;JIAN HongBin;DOU WenZhi;ZHANG Ning;ZHOU DiFan;PENG SiSi;CAI ChuanBing(Shanghai Key Laboratory of High Temperature Superconductors,Department of Physics,Shanghai University,Shanghai 200444,China;Shanghai Creative Superconductor Technologies Co.,Ltd.,Shanghai 201401,China;Wuhan Institute of Marine Electric Propulsion,Wuhan 430070,China)

机构地区：[1]上海大学理学院物理系,上海市高温超导重点实验室,上海200444 [2]上海上创超导科技有限公司,上海201401 [3]中国船舶重工集团公司第七一二研究所,武汉430070

出　　处：《中国科学：物理学、力学、天文学》2023年第12期12-26,共15页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:52172271,52307026);国家重点研发计划项目(编号:2022YFE03150200);上海市科技创新行动计划(编号:22511100200);中科院先导专项(编号:XDB25000000)资助。

摘　　要：在过去的20年,REBCO(REBa_(2)Cu_(3)O_(7-δ),RE=Y,稀土元素)涂层导体被认为是最具应用潜力的超导材料之一.虽然其性能上的研究取得了很大的进展,但仍需要在REBCO薄膜中人工引入有效的磁通钉扎中心以满足更高的在场性能需求.元素掺杂是引入人工磁通钉扎中心常见的手段.在金属有机沉积(Metal-organic Deposition,MOD)制备的REBCO薄膜中,传统元素掺杂引入的异质元素以离子形态分散于前驱薄膜中并在高温过程中以离子扩散的形式生成对应的异质相,一般较难控制其生长、尺寸和分布等.在MOD路线中可采取如中温处理、超薄层涂敷和多元掺杂等多种手段对异质相进行优化,但作用较有限.基于对引入的异质相尺寸和分布上的高要求,采用预先制备特定尺寸的纳米晶后再添加REBCO的技术路线能很好地解决传统元素掺杂遇到的问题,能获得含有尺寸可控的弥散分布纳米晶的REBCO纳米复合薄膜.调整预制条件可得到尺寸在3-15 nm范围内的BaMO_(3)(M=Zr,Hf)纳米晶,经过改性后,单分散于REBCO前驱液和晶化膜中,使每个纳米晶都形成有效的磁通钉扎中心.纳米晶添加技术同样适用于不同厚度的REBCO薄膜,超导层厚度为3.2μm的YBCO纳米复合带材比1.5μm厚的常规YBCO带材在低温30 K@0-7 T范围内在场I_c性能提升了5倍左右.4 mm宽的厚膜带材在4.2 K@20 T的低温高场条件下可实现290 A的载流.另外,因为弥散分布、尺寸可控的纳米晶作为钉扎中心,使得YBCO带材在不同低磁场方向的I_c(77 K)的各向异性受到了明显抑制,趋于各向同性.该技术易于引入产业化生产流程中,并能稳定制备得到长达300-500 m的REBCO长带材,具有高的商业和科研价值.In the past decades,REBa_(2)Cu_(3)O_(7−δ)(REBCO;RE=Y,rare earth element)second-generation high-temperature superconducting coated conductors have been considered one of the most promising superconducting materials.Although much progress and breakthroughs have been made,there remains a need to artificially introduce effective flux pinning centers in REBCO thin films for higher field applications,such as maglev trains,fusion reactors,and generators.Elemental doping is a common method for introducing artificial flux pinning centers.In REBCO films prepared by metal-organic deposition(MOD),the growth,size,and distribution of the doped phases formed by elemental doping are generally more difficult to control at high temperatures.Various approaches,such as medium-temperature treatment,ultrathin coating,and multi-doping strategy,can be adopted in MOD.However,the ability to optimize the doped phases is limited.For satisfying the high requirements of size control and distribution of the doped phases,the pre-prepared nanocrystal addition technique can solve the problems encountered in conventional elemental doping,yielding REBCO nanocomposite films containing randomly distributed nanocrystals of controllable sizes.BaMO3(M=Zr or Hf)nanocrystals with sizes in the range of 3-15 nm can be obtained by adjusting prefabrication conditions and then monodispersed in the REBCO precursor solution and crystallization film after modification such that each nanocrystal can act as an effective flux pinning center.The nanocrystal addition technique can also be applied to REBCO films of different thicknesses.At 30 K,the in-field Ic of a YBCO nanocomposite tape with a superconducting layer thickness of 3.2μm is improved by a factor of~5 compared with that of the conventional YBCO tape with a superconducting layer thickness of 1.5μm.A 4-mm-wide YBCO tape can carry a current of 290 A at 4.2 K in a magnetic field of 20 T.Furthermore,the anisotropy of the in-field Ic at 77 K of YBCO tapes in different magnetic field directions is significan

关 键 词：高温超导 REBa_(2)Cu_(3)O_(7-δ) 人工磁通钉扎 纳米晶 在场载流 

分 类 号：TM26[一般工业技术—材料科学与工程]