Textured YBCO films grown on wires: application to superconducting cables
Textured YBCO films grown on wires: application to superconducting cables
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DOI：
10.1088/0953-2048/25/12/125008
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发表时间：
2012-10
影响因子：
3.6
通讯作者：
N. Dechoux;C. Jiménez;P. Chaudouët;L. Rapenne;E. Sarigiannidou;F. Robaut;S. Petit;S. Garaudée;L. Porcar;J. Soubeyroux;P. Odier;C. Bruzek;M. Decroux
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文献类型：
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作者：
N. Dechoux;C. Jiménez;P. Chaudouët;L. Rapenne;E. Sarigiannidou;F. Robaut;S. Petit;S. Garaudée;L. Porcar;J. Soubeyroux;P. Odier;C. Bruzek;M. Decroux
在La2Zr2O7 （LZO）缓冲和双轴织构Ni-5 at上制备YBa2Cu3O7 （YBCO）超导导线的研究。%W （NiW）的描述。电线是用LZO缓冲NiW带手工成形的。不同的直径生产：1.5,2和3mm。进一步用金属有机化学气相沉积（MOCVD）生长的YBCO覆盖导线。我们开发了一种原始装置，其中圆形基板除了卷轴到卷轴的平移外，还可以围绕其轴进行180°的交替旋转。这种新方法允许用YBCO层覆盖电线的整个圆周。能量色散x射线光谱（EDX）分析与扫描电子显微镜（SEM）相结合证实了这一点。在不同线材直径下，YBCO层厚度在300 ~ 450 nm之间变化，且阳离子组成不变。电子后向散射衍射（EBSD）测量直接在沉积的金属丝上进行，不需要进行表面处理，从而可以研究薄膜表面的结晶质量。结合EBSD和XRD结果，我们发现YBCO在LZO缓冲的NiW线上外延生长。首次在圆形衬底上检测到滚转和圆向的超导行为。通过输运和三次谐波检测，在77 K下测得Jc达到0.3 MA cm−2。这些初步结果证实了MOCVD对于复杂几何形状的有效性，特别是对于在小直径导线上沉积YBCO的有效性。这种方法为新一代ybco基圆形导体的研制开辟了广阔的前景。
Efforts to fabricate superconducting wires made of YBa2Cu3O7 (YBCO) on La2Zr2O7 (LZO) buffered and biaxially textured Ni-5 at.%W (NiW) are described. Wires were manually shaped from LZO buffered NiW tapes. Different diameters were produced: 1.5, 2 and 3 mm. The wires were further covered with YBCO grown by metal organic chemical vapor deposition (MOCVD). We developed an original device in which the round substrate undergoes an alternated rotation of 180° around its axis in addition to a reel-to-reel translation. This new approach allows covering the whole circumference of the wire with a YBCO layer. This was confirmed by energy dispersive x-ray spectroscopy (EDX) analysis coupled to a scanning electron microscope (SEM). For all wire diameters, the YBCO layer thickness varied from 300 to 450 nm, and the cationic composition was respected. Electron backscattering diffraction (EBSD) measurements were performed directly on an as-deposited wire without surface preparation allowing the investigation of the crystalline quality of the film surface. Combining EBSD with XRD results we show that YBCO grows epitaxially on the LZO buffered NiW wires. For the first time, superconductive behaviors have been detected on round substrates in both the rolling and circular direction. Jc reached 0.3 MA cm−2 as measured at 77 K by transport and third-harmonic detection. Those preliminary results confirm the effectiveness of the MOCVD for complex geometries, especially for YBCO deposition on small diameter wires. This approach opens huge perspectives for the elaboration of a new generation of YBCO-based round conductors.