Preparation of CeO/sub 2/-buffer layers for large-area MOD-YBCO films (10/spl times/30 cm/sup 2/) with high-J/sub c/
Preparation of CeO/sub 2/-buffer layers for large-area MOD-YBCO films (10/spl times/30 cm/sup 2/) with high-J/sub c/
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DOI：
10.1109/tasc.2005.847786
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发表时间：
2005-06
影响因子：
1.8
通讯作者：
M. Sohma;I. Yamaguchi;K. Tsukada;W. Kondo;K. Kamiya;S. Mizuta;T. Manabe;T. Kumagai
中科院分区：
文献类型：
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作者：
M. Sohma;I. Yamaguchi;K. Tsukada;W. Kondo;K. Kamiya;S. Mizuta;T. Manabe;T. Kumagai
利用双电子束枪在大面积（最大尺寸为10/spl倍/30 cm/sup 2/） r切割单晶蓝宝石（/spl alpha/-Al/sub 2/O/sub 3/）衬底上沉积了外延氧化铈（CeO/sub 2/；厚度：40 nm）缓冲层。改进了衬底加热和保持系统，以在沉积过程中保持大面积衬底温度均匀。引入压力为4/spl倍/10/sup -2/ Pa的氧气来保持射频等离子体。当衬底温度控制在640/spl°C /-700/spl°C范围内时，通过x射线衍射分析和原子力显微镜观察，在大尺寸衬底的整个区域内，CeO/sub 2/ buffer分别表现出完整的[001]取向和非常光滑的表面。这些缓冲层无需沉积后退火，非常适合在金属乙酰丙酮酸溶液中通过金属有机沉积（MOD）制备YBa/sub 2/Cu/sub 3/O/sub 7/ (YBCO)薄膜。在77.3 K下，电感法测得210 nm厚的MOD-YBCO薄膜的平均临界电流密度超过2.6 MA/cm/sup 2/。
Epitaxial cerium oxide (CeO/sub 2/; thickness: 40 nm) buffer layers were deposited on large area (maximum size 10/spl times/30 cm/sup 2/) R-cut single-crystal sapphire (/spl alpha/-Al/sub 2/O/sub 3/) substrates by double electron-beam guns. Substrate heater-and-holder system was modified to maintain the substrate temperature uniform over the large area during deposition. Oxygen gas of a pressure 4/spl times/10/sup -2/ Pa was introduced to keep radio frequency plasma. When the substrate temperature was controlled in the range 640/spl deg/-700/spl deg/C, the CeO/sub 2/ buffer showed a complete [001] orientation and very smooth surfaces by x-ray diffraction analysis and atomic force microscopic observations, respectively, in the whole area of the large size substrates. These buffer layers without post-deposition annealing were quite suitable for preparing YBa/sub 2/Cu/sub 3/O/sub 7/ (YBCO) films by a metal-organic deposition (MOD) using a metal acetylacetonate-based solution. The average critical current density of the 210-nm-thick MOD-YBCO film was in excess of 2.6 MA/cm/sup 2/ measured by an inductive method at 77.3 K.