Surface characterization of as-grown CeO2 cap layer morphology evolution and critical current density of post-deposited YBCO films
Surface characterization of as-grown CeO2 cap layer morphology evolution and critical current density of post-deposited YBCO films
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生长后 CeO2 盖层形貌演变的表面表征和沉积后 YBCO 薄膜的临界电流密度
DOI：
10.1166/mex.2015.1265
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发表时间：
2015
影响因子：
0.7
通讯作者：
Z. H. Han
中科院分区：
文献类型：
--
作者：
F. Feng;Y. Y. Zhang;T. M. Qu;R. X. Huang;S. Z. Xiao;Y. P. Zhu;H. Y. Lu;K. Shi;Z. F. Hou;Z. H. Han
采用非平衡射频磁控溅射法在氧化钇稳定氧化锆（YSZ）单晶衬底上制备了高温超导涂层导体用CeO 2帽层。采用无水金属有机物沉积（MOD）法在CeO 2/YSZ（001）叠层上外延生长YBa 2Cu 3 O 7-δ（YBCO）薄膜。CeO 2盖层的表面形貌演变可以通过调节溅射压力来调节，从光滑和均匀的颗粒状，粗糙和纺锤状的岛屿组成。根据原子力显微镜（AFM）的数据，均方根（RMS）粗糙度值和平坦面积分数之间的单调关系可以找到。MOD-YBCO薄膜的临界电流密度（Jc）随着CeO 2形貌的变化而沿着变化，这是由于YBCO薄膜外延生长过程中的退化造成的.结果表明，在0.5Pa下沉积的CeO 2帽层可以作为一个良好的模板，无需后处理，在其上可以得到Jc为1.92MA/cm 2（77 K，自场）的YBCO薄膜.在今后的研究中，我们将通过优化MOD工艺参数来提高YBCO薄膜的Jc性能。
Cerium dioxide (CeO2) cap layers for high temperature superconducting coated conductors were fabricated on yttria-stabilized zirconia (YSZ) single crystal substrates via the unbalanced radio frequency (RF) magnetron sputtering method. YBa2Cu3O7–δ (YBCO) films were epitaxially deposited on the as-grown CeO2/YSZ (001) stacks using water-free metal organic deposition (MOD) method. The surface morphology evolution of CeO2 cap layers could be tuned by adjusting the sputtering pressure, from smooth and uniformly granular, to rough and composed of spindle-like islands. According to the atomic force microscopy (AFM) data, a monotonic relationship could be found between the root mean squared (RMS) roughness value and flat area fraction. The critical current density (J c) of the MOD-YBCO film varied significantly along with the CeO2 morphology evolution, caused by the degradation of YBCO film's epitaxial growth. It was found that the as-grown CeO2 cap layer deposited at 0.5 Pa could serve as a favorable template and did not require post-modification, on which YBCO film with J c of 1.92 MA/cm2 (77 K, self-field) could be obtained. The MOD process would be improved in our future study by parameter optimization to enhance the J c property of YBCO films.