采用钙钛矿导电缓冲层提高YBCO涂层导体临界电流密度的可行性研究  

Feasibility study of improving the critical current density of YBCO coated conductor with perovskite conductive buffer layer

作　　者：李凤华[1] 罗清威[1] 李英楠[1] 樊占国[1] 

机构地区：[1]东北大学材料与冶金学院,沈阳110004

出　　处：《材料与冶金学报》2010年第3期189-192,201,共5页Journal of Materials and Metallurgy

基　　金：国家青年科学基金资助(50702012);国家高技术研究发展计划项目(2008AA03Z202);辽宁省博士启动基金资助(20071017)

摘　　要：以Ni合金为基底的YBCO涂层导体具有三明治结构,从下至上分别是:Ni合金、缓冲层、YBCO涂层与稳定层.在实用超导薄膜内部,局域超导电流由于晶粒弱连接、缺陷或裂纹等原因突然消失的情况下,一旦能量耗散超过临界值将会导致超导薄膜失超.在典型的YBCO涂层导体结构中,由于缓冲层是绝缘的氧化物,只能通过顶层的Ag或Cu稳定层的分流来实现电流传输方向的调整.如果在YBCO与正常金属基底之间存在连续的导体连接,即缓冲层导电,就可以不需稳定层,减少涂层导体的整体厚度,提高工程临界电流密度JE.如果钙钛矿导电缓冲层均匀无裂纹且足够厚,就可以起到隔离、外延、电流传输三重功效,同时提高JE.采用全化学溶液法制备了具有(00l)择优取向的BaPbO3,La0.5Sr0.5TiO3钙钛矿导电缓冲层与YBCO涂层,对于探索低成本的实用化工艺路线具有重要的实际应用价值.YBCO coated conductor on Ni alloy substrate is of sandwich structure, from the bottom to top, respectively, Ni alloy, the buffer layer, YBCO layer and the stable layer. Within the practical superconducting films, once the energy dissipation, caused by grain weak link , defects or cracks and other reasons, exceeds the critical value, the superconducting film will quench suddenly. In order to solve this, the top layer of conductive Ag or Cu is coated as split flow, which could adjust the current transport direction in the typical YBCO coated conductor structure. If the buffer layer between YBCO and normal metal base is conductive, not only the stable layer is unnecessary but also the engineering critical current density JE is improved by reducing the overall thickness of the coated conductor. If the perovskite conductive buffer layer is uniform, crack-free and thick enough, it can play triple effects of separation, epitaxy and current transmission as well as improving the JE. Using all chemical solution method, BaPbO3, La0.5Sr0.5TiO3 perovskite conductive buffer layer and YBCO coat were prepared with （00l） preferred orientation. It shows important practical value for developing the low-cost practical technological process.

关 键 词：YBCO涂层导体 导电缓冲层 钙钛矿 临界电流密度 

分 类 号：TM262[一般工业技术—材料科学与工程]