Preparation of High-Jc YBa2Cu3O7-y Films on CeO2-Buffered Yttria-Stabilized Zirconia Substrates by Fluorine-Free Metalorganic Deposition
Preparation of High-Jc YBa2Cu3O7-y Films on CeO2-Buffered Yttria-Stabilized Zirconia Substrates by Fluorine-Free Metalorganic Deposition
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DOI：
10.1143/jjap.44.4914
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发表时间：
2005-07
影响因子：
1.5
通讯作者：
K. Tsukada;M. Furuse;M. Sohma;T. Manabe;I. Yamaguchi;W. Kondo;S. Fuchino;T. Kumagai
中科院分区：
文献类型：
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作者：
K. Tsukada;M. Furuse;M. Sohma;T. Manabe;I. Yamaguchi;W. Kondo;S. Fuchino;T. Kumagai
采用无氟金属有机物沉积法在YSZ衬底上制备了YBa 2Cu 3 O 7-y（YBCO）外延薄膜。采用金属乙酰丙酮盐镀膜液制备的YBCO薄膜，经X射线衍射θ-2θ扫描和φ扫描，均具有高度的（001）取向。0.21 μ m厚的YBCO薄膜表现出高超导转变温度，Tc=90.1 K，和高临界电流密度，使用电感法在77 K时平均超过4 MA/cm 2。传输临界电流（Ic）也测量了一个标准的四端技术; Ic值达到185 A，在2.5厘米宽的电流路径上形成的5厘米直径的薄膜。这些优异的性能归因于YBCO薄膜的高度外延导致的小的面内波动，这是由于YBCO薄膜、CeO 2缓冲层和YSZ衬底之间的晶体结构、晶格参数和热膨胀系数之间的良好匹配，以及YBCO薄膜的光滑和均匀的表面形貌，CeO 2缓冲层的平均粗糙度= 0.34 nm。本发明的沉积条件，即，在700°C和p（O2）=4×10-2 Pa的条件下，用20 W的射频等离子体激活，可以在YSZ衬底上生长CeO 2（100）缓冲层。
Epitaxial YBa2Cu3O7-y (YBCO) films have successfully been prepared by fluorine-free metalorganic deposition on yttria-stabilized zirconia (YSZ) substrates with an evaporated CeO2 buffer layer. The YBCO films, prepared using a metal acetylacetonate-based coating solution, were highly (001)-oriented by X-ray diffraction θ–2θ scanning and φ scanning. The 0.21-µm-thick YBCO film demonstrated a high superconducting transition temperature, Tc=90.1 K, and high critical current densities with an average in excess of 4 MA/cm2 at 77 K using an inductive method. Transport critical current (Ic) was also measured by a standard four-terminal technique; the Ic value reached 185 A in a 2.5-cm-wide current path formed on a 5-cm-diameter film. These excellent properties are attributed to the small in-plane fluctuation due to high epitaxy of the YBCO films, which resulted from good matching of the crystal structure, lattice parameter and thermal expansion coefficient among the YBCO film, CeO2 buffer layer and YSZ substrate, as well as from the smooth and uniform surface morphology, i.e., average roughness = 0.34 nm, of the CeO2 buffer layer. The present deposition conditions, i.e., 700°C and p(O2)=4×10-2 Pa, activated by radio frequency plasma at 20 W, are valid for the growth of such CeO2(100) buffer layers on YSZ substrates.