斜切基片上c-取向YBa_2Cu_3O_(7-δ)薄膜的生长特性及开裂行为  

Growth Properties and Cracking Behavior of c-axis YBa_2Cu_3O_(7-δ) Films Grown on Vicinal Substrates

作　　者：王天生[1] 漆汉宏[1] 田永君[1] 胡文斐[2] 赵新杰[2] 陈莺飞[2] 李林[2] 

机构地区：[1]燕山大学材料科学与工程学院,秦皇岛066004 [2]中国科学院物理研究所,北京100080

出　　处：《真空科学与技术》2001年第6期470-472,共3页Vacuum Science and Technology

基　　金：国家自然科学基金资助项目 (No .5 9832 0 5 0 )

摘　　要：用脉冲激光沉积方法在斜切SrTiO3 (0 0 1)基片上制备了YBa2 Cu3 O7 δ薄膜 ,并用原子力显微镜、X射线衍射仪及透射电镜研究了薄膜表面形貌、取向特征、结晶性和显微结构。结果表明 ,薄膜表面呈“台阶 台面”结构 ,并伴有与台阶边缘垂直的裂纹产生 ,说明薄膜以“台阶流动”方式生长 ;而且薄膜具有c 轴取向 ,但其结晶性不好。在薄膜中没有观察到a b孪晶的存在。薄膜的开裂和结晶性较差均是由于斜切基片台阶表面晶格四方畸变抑制了薄膜正交转变时a b孪晶的产生 ,而使晶格错配应变不能释放造成的。YBa 2Cu 3O 7- δ superconducting films have been prepared on vicinal SrTiO 3(001) substrates by pulsed laser deposition method.The surface morphology,oriented feature,crystallinity and microstructure of the films have been studied by using atomic force microscopy,X-ray diffractometry and transmission electron microscopy.The results show that the surfaces of the films display the step-terrace structure with cracks normal to the step edges,suggesting the films grow in step-flow mode,and the films are c -axis oriented but the crystallinity is poor. a-b twin is not examined in the films.The crack formation and the poor crystallinity of the films are attributed to the fact below.The tetragonal distortion in surface lattice of the vicinal substrates suppresses the a-b twin formation in the films during orthorhombic transition.So the lattice mismatch strain cannot be relaxed,consequently leading the cracks.

关 键 词：高温超导体 生长 斜切基片 脉冲激光沉积 开裂行为 YBA2CU3O7-Δ 钙钛矿型氧化物 超导薄膜 

分 类 号：TM26[一般工业技术—材料科学与工程] O484[电气工程—电工理论与新技术]