插入二氧化铈薄膜提高MOD-YBa_2Cu_3O_(7-x)厚膜超导性能的研究  

Enhanced superconducting properties in MOD-YBCO thick films with CeO_2 interlayer

作　　者：丁发柱[1,2] 古宏伟[1,2] 王洪艳[1,2] 屈飞[1,2] 商红静 张慧亮[1,2] 董泽斌 张贺[1,2] 周微微[1,2] 

机构地区：[1]中国科学院电工研究所,北京100190 [2]中国科学院应用超导重点实验室,北京100190 [3]青岛科技大学材料科学与工程学院,青岛266042

出　　处：《物理学报》2016年第9期310-316,共7页Acta Physica Sinica

基　　金：国家高技术研究发展计划(批准号:2014AA032702);国家自然科学基金(批准号:51577180;51272250);北京市自然科学基金面上项目(批准号:2152035)资助的课题~~

摘　　要：YBa_2Cu_3O_(7-x)(YBCO)膜存在"厚度效应":随着厚度增加,YBCO薄膜的临界电流密度下降,尤其是YBCO薄膜的厚度超过1μm时,它的临界电流密度急剧下降.本文在YBCO薄膜之间引入极薄的二氧化铈(CeO_2)薄膜,成功制备出结构为YBCO/YBCO/CeO_2/YBCO的超导厚膜.所制备的厚度为2μm的YBCO膜临界电流密度为1.36 MA/cm^2(77 K,自场),其性能比相同厚度的纯YBCO膜有了较大幅度的提升.研究表明CeO_2薄膜起到了传递织构、松弛应力的作用.In YBa_2Cu_3O_（7-x）（YBCO） film there exists ＂thickness effect＂：the critical current density of YBCO film drops precipitously as the coating thickness increases,especially in the case that the thickness of YBCO film exceeds 1 μm.In this paper,we introduce very thin layers of CeO_2 into YBCO layers and successfully fabricate the structure of YBCO/YBCO/CeO_2/YBCO superconducting thick film.Firstly,YBCO films with two layers are fabricated on a LaAlO_3 substrate by a multiple coatings process using a trifluoroacetate metal organic deposition method.Secondly,CeO_2 thin films are deposited on YBCO films by RF-sputtering.Finally,we prepare the third YBCO film on CeO_2 interlayer.No cracks are observed in scanning electron microscopy images of these films;further,the majority of the grains in the films are well-textured and c-axis oriented.The full-width-half-maximum of the out-of-plane texture is measured to be 1.395？for the multilayer YBCO film at a thickness of 2 μm Using this multilayer technology,we achieve Jc values of up to1.36 MA/cm^2（77 K,self-field） in films as thick as 2 μm,for an extrapolated critical current of 272 A/cm.We attribute the enhanced performance of the thick YBCO film to the CeO_2 interlayer which playsan important role in transmission texture and stress relaxation.

关 键 词：钇钡铜氧 二氧化铈插层 厚膜 

分 类 号：O511.3[一般工业技术—材料科学与工程] O484[理学—低温物理]