Transport performance of Bi-2212 current leads prepared by a diffusion process
Transport performance of Bi-2212 current leads prepared by a diffusion process
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扩散工艺制备的 Bi-2212 电流引线的传输性能
DOI：
10.1109/77.920389
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发表时间：
2001
影响因子：
1.8
通讯作者：
T. Mito
中科院分区：
文献类型：
--
作者：
Y. Yamada;M. Takiguchi;O. Suzuki;K. Tachikawa;A. Iwamoto;H. Tamura;T. Mito
用扩散法制备了Bi-2212块体圆柱体，用于当前的铅应用。Bi-2212氧化物超导层是通过Sr-Ca-Cu氧化物管状衬底与添加Ag的Bi-Cu氧化物涂层之间的反应合成的。Bi-2212扩散层的厚度约为150 μ/m，具有围绕外径/内径为20/16 mm的管形成的织构结构。在4.2K下，在自场下，管状样品的输运电流超过6.250A，这对应于35，000 A/cm/sup 2/的输运电流密度。在样品的两端，由Cu端盖、Sn-Pb焊料和样品上的Ag接触组成的总接头电阻被测量为约150 m/spl Ω/。在4.2K时，Sn-Pb钎料的电阻率约为2n/spl Ω/m，比Cu和Ag钎料的电阻率高一个数量级。因此，焊接工艺在降低接头电阻和由此产生的焦耳热方面很重要。目前的Bi-2212超导体具有很大的传输电流，有望作为超导磁体的电流引线。
Bi-2212 bulk cylinders have been prepared by the diffusion process for current lead application. The Bi-2212 oxide superconducting layer is synthesized through the reaction between a Sr-Ca-Cu oxide tubular substrate and a Bi-Cu oxide coating layer with Ag addition. The Bi-2212 diffusion layer about 150 /spl mu/m in thickness with textured structure formed around a tube 20/16 mm in outside/inside diameter. The transport current of the tube specimen exceeds 6.250 A at 4.2 K under self-field, which corresponds to a transport current density of 35,000 A/cm/sup 2/. The overall joint resistance is measured to be about 150 m/spl Omega/ at both ends of the specimen, composed of Cu endcap, Sn-Pb solder and Ag contact on the specimen. The resistivity of the commercial Sn-Pb solders is About 2 n/spl Omega/m at 4.2 K, and one order of the magnitude higher than that of Cu and Ag. Therefore, the soldering process is important in reducing the joint resistance and the resultant Joule heat. Present Bi-2212 bulk conductors with large transport current are promising as current leads for superconducting magnets.