| 1. |
- Koblischka, M. R., et al.
(författare)
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Magneto-optic imaging of flux penetration into an artificially granular high-Tc superconductor
- 1999
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Ingår i: Advances in Superconductivity XI. Proceedings of the 11th International Symposium on Superconductivity (ISS'98). - 4431702563 ; 2, s. 693-696
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A YBa2Cu3O7- (YBCO) thin film is patterned into a hexagonal close packed lattice of disks which are touching each other at the circumferences in order to enable the flow of an intergranular current. Such a sample was suggested by Koblischka et al. [Appl. Phys. Lett 70, 514 (1997)] as a model for a layered granular structure like in a Bi2Sr2Ca2Cu3O10- tape. Magnetization measurements reveal an anomalous position of the low field peak (central peak) similar to the tapes. Magneto-optic imaging is employed to visualize the local field distributions
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| 2. |
- Koblischka, M. R., et al.
(författare)
-
Paramagnetic Meissner response of an artificially granular YBCO thin film
- 2000
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Ingår i: Physica B: Condensed Matter. - 0921-4526. ; 284-288, s. 599-600
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Konferensbidrag (refereegranskat)abstract
- Field-cooling measurements on an YBa2Cu3Oy thin film, patterned into a hexagonal close-packed lattice of disks with a diameter of 50 m reveal a paramagnetic Meissner response (PME) when cooled in fields below 1 mT. In contrast to previous investigations on Nb and melt-cast Bi-2212, the PME in this artificial granular film is attributed to field trapping in the space between the disks
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| 3. |
- Koblischka, M. R., et al.
(författare)
-
Flux distributions of an artificially granular YBa2Cu3O7- thin film observed using magneto-optic imaging
- 2000
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Ingår i: Physica C: Superconductivity and its Applications. - 0921-4534. ; 331, s. 113-26
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Tidskriftsartikel (refereegranskat)abstract
- Flux distributions in a YBa2Cu3O7- thin film with artificial granularity are observed by means of magneto-optic imaging. At low magnification, flux patterns generated exclusively by the intergranular currents flowing in the intergranular area (effective medium) are directly observed. The properties of this effective medium are studied by taking flux density profiles that reveal the intergranular current density. As the observations at high magnifications show the flux penetration and pinning within the individual disks, we can identify and study the different contributions of the intergranular and intragranular current densities to the flux patterns. We show that our model sample reproduces several features observed, e.g., in Ag-sheathed (Pb,Bi)2Sr2Ca2Cu3O10+ tapes
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