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Magnetic field depe...
Magnetic field dependence of the critical current density for the bismuth-based bulk high-Tc superconductors
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- Guo, S.J. (författare)
- Luleå tekniska universitet
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Loberg, Bengt (författare)
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- Dou, S.X. (författare)
- University of New South Wales
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visa fler...
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- Liu, H.K. (författare)
- University of New South Wales
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visa färre...
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(creator_code:org_t)
- 1992
- 1992
- Engelska.
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Ingår i: Journal of Materials Science. - 0022-2461 .- 1573-4803. ; 27:11, s. 3043-3049
- Relaterad länk:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- Three types of bismuth-based bulk samples were prepared through uniaxial pressing at room temperature, hot isostatic pressing (HIP) and drawing and rolling. Transport current properties were characterized in a steady field up to 1.12 T at 77 K (T/T c=0.75). The Josephson weak-link decoupling fields have been found to be 5 mT for the cold-pressed pellet and 30 mT for the HIPed pellet and the rolled tape. At the decoupling field the transport critical current density,J c, drops 80% from 124 (OT) to 29 A cm-2 (5 mT) for the cold-pressed pellet, 80% from 582 (OT) to 126 A cm-2 (30 mT) for the HIPed sample and 50% from6500 (0 T) to 2850 A cm-2 (30 mT) for the rolled tape. In the flux flow regime, whereB is perpendicular to thec-axis a modified Kim's modelJ c=(α/B 0)/[(1+B/B 0)] n can be used to describe the field dependence of the critical current density, Jc, in the field range 0.2-1.12 T. The effective upper critical fields were estimated to be 0.98, 1.54 and 1.94 T for the three types of samples, respectively. An adjustable range ofB c2 for bismuth-based bulk highT c superconductors is given. Flux shear may operate in these materials. The prediction of this pinning mechanism is yielded from fitting the equation qualitatively. WhenB is parallel to thec-axis, the absence of strongly intragranular flux-pinning is emphasized by the poor flux flow regime for the rolled tape sample.
Ämnesord
- TEKNIK OCH TEKNOLOGIER -- Materialteknik -- Annan materialteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Materials Engineering -- Other Materials Engineering (hsv//eng)
Nyckelord
- Materialteknik
- Engineering Materials
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