【作者】 朱传凤； 王琛； 杨林静； 商广义； 李建伟； 李清； 赵伯儒； 郑丽珍； 孙吉军；

【Author】 Zhu Chuanfeng Wang Chen Yang Linjing Shang Guangyi Li Jianwei Li Qing (Institute of Chemistry,Chinese Academy of Sciences,Beijing 100080,China) Zhao Boru Zheng Lizhen Sun Jijun (Institute of Physics,Chinese Academy of Sciences,Beijing 100080,China)

【机构】 中国科学院化学研究所； 中国科学院物理研究所；

【摘要】 本文报道用原子力显微镜（AFM）研究的几种（YBCO）超薄膜的表面结构,这些膜分别生长在 SrTiO₃（100）基底,和具有厚度为40nm 的 PrBa₂Cu₃O₇缓冲层的 SrTiO₃基底上,YBCO 超薄膜厚度范围为2．5nm—25nm。在2．5nm 厚的单层膜表面观察到了岛状结构,并在7．5nm 厚的超薄膜表面首次观察到了台阶高度不同的三种螺旋位错。同时还讨论了 YBCO 超薄膜的生长机理。更多还原

【Abstract】 The screw dislocations of ultrathin YBa₂Cu₃O₇（YBCO）films with the thickness ranging from 2.5 nm to 25 nm have been studied by atomic force microscope（AFM）at room temperature（17.5℃）.The YBCO films were grown on the SrTiO₃（100）crystal substrate with or without 40 nm-thick-buffer layer of PrBa₂Cu₃O₇, respectively.The AFM data indicated that the films grow with spiral and layer by layer growth modes,and the screw dislocation is a typicl spiral growth mode.Three kinds of screw dislocations were found on the 7.5 nm thick films with buffer layer.However,all kinds of the screw dislocations have a common feature that the top of the screw dislocations is a columnar core which the height is 4 times greater than the length of the c-axis. Moreover,the 2-D growth mode along the film plane are discussed.更多还原