Anisotropy of strong pinning in multi-band superconductors

TitleAnisotropy of strong pinning in multi-band superconductors
Publication TypeJournal Article
Year of Publication2012
Authorsvan der Beek CJ, Konczykowski M, Prozorov R
Journal TitleSuperconductor Science & Technology
Date Published08
Type of ArticleArticle
ISBN Number0953-2048
Accession NumberWOS:000306505100011
Keywordsboson localization, columnar defects, flux-line-lattice, high-temperature superconductors, ii superconductors, layered superconductors, lock-in transition, single-crystals, vortex line, yba2cu3o7-delta

The field-angular dependence and anisotropy of the critical current density in iron-based superconductors is evaluated using a phenomenological approach featuring distinct anisotropy factors for the penetration depth and the coherence length. Both the weak collective pinning limit and the strong pinning limit relevant for iron-based superconductors at low magnetic fields are considered. It is found that in the more anisotropic materials, such as SmFeAsO and NdFeAsO, the field-angular dependence is completely dominated by the coherence length (upper critical field) anisotropy, thereby explaining recent results on the critical current in these materials. In less anisotropic superconductors, strong pinning can lead to an apparent inversion of the anisotropy. Finally, it is shown that, under all circumstances, the ratio of the c-axis and ab-plane critical current densities for the magnetic field along the ab-plane directly yields the coherence length anisotropy factor epsilon(xi).

URL<Go to ISI>://WOS:000306505100011
Alternate JournalSupercond. Sci. Technol.