Transport Properties of Melt-cast Processed Bi-2212 Bulk Superconductor Bars
Transport Properties of Melt-cast Processed Bi-2212 Bulk Superconductor Bars
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熔铸加工 Bi-2212 块体超导棒的输运特性
DOI：
10.1109/tasc.2014.2360584
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Hiroya Andoh and Takehiko Tsukamoto
中科院分区：
文献类型：
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作者：
Dai Oikawa;Yu Higashi;Hideaki Muronani;Toko Sugiura;Hiroya Andoh and Takehiko Tsukamoto
高临界温度超导体（HTSs）块体材料由于在电流传输下可忽略的小焦耳加热和非常低的热导率而有希望用作电流引线和故障电流限制器。我们认为采用熔铸工艺（MCP）制备的Bi-2212块体超导体是这些应用的最佳材料之一。此外，MCP是众所周知的是一个简单和经济的过程，也作为一种方法来获得任何大小的HTS散装同意的要求，为实际应用。本文研究了掺K_2CO_3的Bi-2212超导体的输运和猝灭特性。首先，通过使用X射线衍射仪和X射线荧光光谱仪对K2 CO 3掺杂的MCP样品进行分析。此外，还观察到了K2 CO 3掺杂的MCP样品的临界温度。研究了临界电流值与K_2CO_3掺杂量的关系。直流临界电流的值在77 K下确定，并且使用1 μV/cm的标准获得由电场与输运电流特性导出的自场。最后，测量了MCP样品的交流输运特性，并讨论了临界电流随电流分布的频率依赖性。
Bulk materials of high-critical-temperature superconductors (HTSs) are promising for current leads and fault-current limiters because of negligibly small Joule heating under current transport and very low thermal conductivity. We consider that a Bi-2212 bulk superconductor prepared by the melt-casting process (MCP) is one of the best materials for these applications. In addition, MCP is well known to be a simple and economic process, and also served as a method for obtaining any sizes of HTS bulks consent to requirements for practical applications. In this paper, we present a study on the transport and quench properties of Bi-2212 bulk superconductors doped with K2CO3. First, the MCP samples doped with K2CO3were analyzed by using an X-ray diffractometer and X-ray fluorescence spectrometry. In addition, the critical temperatures of the MCP samples doped with K2CO3were observed. Then, we have investigated the relations between the critical current value and the doping quantity of K2CO3. The value of the direct-current critical current was determined at 77 K, and the self-fields derived from the electric field versus the transport current characteristics were obtained using a criterion of 1 μV/cm. Finally, the alternating-current transport properties of the MCP sample were measured, and we have discussed the frequency dependence of the critical current with current distributions.