| Autor: |
Rush, JP, May-Miller, CJ, Palmer, KGB, Rutter, NA, Dennis, AR, Shi, YH, Cardwell, DA, Durrell, JH |
| Přispěvatelé: |
Dennis, Tony [0000-0003-4962-7149], Cardwell, David [0000-0002-2020-2131], Durrell, John [0000-0003-0712-3102], Apollo - University of Cambridge Repository |
| Jazyk: |
angličtina |
| Rok vydání: |
2016 |
| Předmět: |
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| Popis: |
The characterisation of the critical current density of bulk high temperature superconductors is typically performed using magnetometry, which involves numerous assumptions including, significantly, that Jc within the sample is uniform. Unfortunately, magnetometry is particularly challenging to apply where a local measurement of Jc across a feature, such as a grain boundary, is desired. Although transport measurements appear to be an attractive alternative to magnetization, it is extremely challenging to reduce the cross-sectional area of a bulk sample sufficiently to achieve a sufficiently low critical current that can be generated by a practical current source. In the work described here, we present a technique that enables transport measurements to be performed on sections of bulk superconductors. Metallographic techniques and resin reinforcement were used to create an I-shaped sample of bulk superconductor from a section of Gd-Ba-Cu-O containing 15 wt % Ag2O. The resulting superconducting track had a cross-sectional area of 0.44 mm2. The sample was found to support a critical current of 110 A using a field criterion in the narrowed track region of 1 μV cm-1. We conclude, therefore, that it is possible to measure critical current densities in excess of 2.5 x 108 A m-2 in sections of a bulk superconductor. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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