Flux pinning and vortex dynamics in MgB2 doped with TiO2 and SiC inclusions
| Autor: | J.-H. Kang, V. G. Prokhorov, T. W. Eom, V. L. Svetchnikov, YoungPak Lee, V. A. Khokhlov, G. G. Kaminsky, Junghum Park, Pavlo Mikheenko |
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| Rok vydání: | 2009 |
| Předmět: |
Superconductivity
Flux pinning Materials science Physics and Astronomy (miscellaneous) Condensed matter physics General Physics and Astronomy Coherence length Condensed Matter::Materials Science Paramagnetism Meissner effect Condensed Matter::Superconductivity Type-II superconductor Critical field Pinning force |
| Zdroj: | Low Temperature Physics. 35:439-448 |
| ISSN: | 1090-6517 1063-777X |
| DOI: | 10.1063/1.3151990 |
| Popis: | The mixed-state superconducting properties of bulk MgB2+2at.%TiO2 and +8at.%SiC, prepared by in situ solid state reaction, are investigated. Analysis of the mixed-state parameters, such as the upper critical field, the coherence length, and the Ginzburg-Landau parameter, proves that MgB2+2at.%TiO2 is a high-κ type-II superconductor in the dirty limit, while MgB2+8at.%SiC corresponds to that in the moderately clean limit. It is shown that the grain-boundary pinning realized in fine-grained doped MgB2 polycrystals is of the anisotropic rather than the electron-scattering type. The field-cooled temperature dependences of the magnetic moment reveal a transition of the samples to the paramagnetic state at certain applied magnetic fields, which is treated as manifestation of the paramagnetic Meissner effect. The experimental results are discussed on the base of modern theoretical approaches. |
| Databáze: | OpenAIRE |
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