Y_2O_3缓冲层对YBCO超导转变温度的影响（英文）  

EFFECT OF Y_2O_3BUFFER LAYER ON SUPERCONDUTING TRANSITION TEMPERATURE OF YBCO FILMS

作　　者：武传宝[1] 赵高扬[1] 雷黎[1] 赵瑞[1] 瞿贵峰 

机构地区：[1]西安理工大学材料科学与工程学院,西安710048

出　　处：《低温物理学报》2014年第2期81-85,共5页Low Temperature Physical Letters

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.51072163,51202190);Natural Science Basic ResearchPlan in Shaanxi Province of China(Grant No.2012JQ6016)~~

摘　　要：超导薄膜所受的应力对其临界转变温度Tc具有重要的影响,研究应力对超导薄膜Tc的影响对获得更高Tc材料具有重要意义.本文采用溶胶-凝胶法,在LAO单晶基板上制备了Y2O3/YBCO薄膜,并研究了Y2O3缓冲层对不同厚度YBCO超导薄膜的临界转变温度的影响.研究发现,当YBCO薄膜厚度为90nm时,由于Y2O3和YBCO薄膜的晶格错配,在YBCO/Y2O3薄膜的a-b面内引入了压应力,增加了c轴的晶格常数,结果提高了YBCO薄膜的临界转变温度.当YBCO薄膜的厚度较大时(如230nm),由晶格错配引起的应力通过位错的形式得以释放,YBCO薄膜的Tc变化不大.The strain in superconductor films plays an important role in improving superconducting critical transi- tion temperature （To）. In order to obtain higher Tc YBCO superconducting film, it is necessary to investigate the effect of the strain on the microstructures and properties of YBCO film. In the paper, YBCO films were prepared on Y2O3 buffered LAO substrates using sol-gel method, and the effect of thickness of YBCO films on Tc was investiga- ted. The results show that Tc of the film was enhanced when the thickness of YBCO film was 90 nm, which is inter- preted as follow. Due to the lattice mismatch between Y2 03 and YBCO films, the compressive epitaxial strhin was introduced into a-b plane of YBCO films, which increased the lattice constant in c-axis direction of YBCO and thus enhanced To. When the thickness of YBCO film is 230 nm, the strain derived from the lattice mismatch is released as a result of the formation of some defects, so Tc of the film is almost unchanged.

关 键 词：YBCO 应力 临界转变温度 Y2O3 

分 类 号：O484[理学—固体物理]