| Project/Area Number |
13650361
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | Toyota National College of Technology |
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Principal Investigator |
TSUKAMOTO Takehiko Department of Electrical and Electronic Engineering, Associate Professor, 電気・電子システム工学科, 助教授 (10217284)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2002: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2001: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Melt-Casting Process / Bi-2212 Bulk Superconductor / Effect of Li Addition / AC Transport Losses / Critical Current / Critical Temperature / Transport Properties / Current Lead / 臨界電流密度分布 / n値 / 交流損失 / 導電特性 / Li添加 |
|---|
| Research Abstract |
The Bi-2212 bulk superconductors, with a proper amount of SrSO_4, were prepared by melt-casting process (MCP). Critical current in bulk Bi2212 bar (φ10.7mm) exceeded 50A at 77K. The weak links have been largely eliminated in the MCP sample. The enhancement of transport properties is due to the addition of lithium carbonate (Li_2CO_3). The maximum critical temperature occurs for the MCP sample Bi_2Sr_2CaCu_2Li_<0.2>O_y annealed at 800°C. And, we have investigated the ac transport losses and critical current density distribution of MCP samples. The ac losses are mainly ascribed the hysteresis loss of the superconductor. The ac loss value is about one-half of the theoretical value obtained by the theory of Norris. The local J_c value decreases significantly in going from the surface to the interior of the sample, which suppresses the extension of the flux-penetration-region to the interior under ac current transmission and lowers the loss generation compared with the calculated results obtained by the uniform J_c distribution. Present MCP Bi-2212 bulk superconductors seem to be promising as a current lead.
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