2003 Fiscal Year Final Research Report Summary
Preparation of Large size Bi-based Superconducting Single Crystals with High Critical Current Density
| Project/Area Number |
14550019
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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 |
Applied materials science/Crystal engineering
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| Research Institution | Matsue National College of Technology |
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Principal Investigator |
IMAO Hiroya Matsue National College of Technology, Department of Control Engineering, Associate Professor, 電子制御工学科, 助教授 (50203310)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUMOTO Kosuke Matsue National College of Technology, Department of Control Engineering, Associate Professor, 電子制御工学科, 助教授 (60249836)
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| Project Period (FY) |
2002 – 2003
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| Keywords | Bi-based Superconductor / Single Crystal / Critical Current Density |
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| Research Abstract |
In order to apply Bi_2Sr_2Ca_<m-1>Cu_mO_<2m+4+δ>(Bi-based) superconductor into the field of power electronics, it is important to prepare it with a high critical current density (Jc). In this study, we prepared the Bi-based superconducting single crystals by a self-flux method and investigated the effects of the growth condition on the Jc, Tc, crystal sizes and weights of crystals.
We grew the Bi_2Sr_2CaCu_2O_x (Bi-2212) single crystals by a self-flux method, where the Bi-2212 single crystals prepared at the first growth were used as a starting material in the second growth. This is called re-growth method. The size of the crystals prepared in the second growth was larger than that prepared in the first growth. Therefore, to use the Bi-2212 single crystals as starting materials is effective for obtaining large Bi-2212 single crystals. From the results of XRD pattern and of R-T characteristics, we found that the single crystals prepared by the re-growth method had a Bi-2212 superconductor and did not contain any impurity phases.
Large volumes of the single crystals were obtained by using the large crucibles. When smaller crucibles were used, the 30% volume of the starting materials became the single crystals. The rate of single crystals to the starting materials prepared by the large crucibles were larger than those prepared by the small crucibles. The weight of the single crystals prepared at the cooling rate of 1℃/h was about 130g. The results indicate that the single crystal corresponds to the 65% weight of the starting materials. Therefore, the large crucibles are useful for effective production of Bi-2212 single crystals.
However, the measurement of critical current is difficult because of the instability of the electrodes formed on the surfaces of single crystals. We need the research of the electrode formation on to the single crystal surfaces to the step of the growth of the high Jc single crystals.
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Research Products
(14 results)
