Collective dynamics of a highly dilute vortex lattice in YBa2Cu3O7-delta thin films
2002 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 65, no 13Article in journal (Refereed) Published
The dynamics of highly dilute vortex ensembles in YBa2Cu3O7-delta thin films is investigated by low-field (5-90 Oe) ac susceptibility measurements of the dynamical relaxation rate Q. In a film with relatively weak pinning, flux bundling is found to be effective at all temperatures and down to the lowest fields. In a film with stronger pinning, single-vortex creep dominates only for T<20 K, and small bundle creep is fully developed for T>40 K. The behavior of highly separated vortices is hence surprisingly collective in YBa2Cu3O7-delta. Quantum creep is observed below 11 K, and at about 60 K the elastic vortex description breaks down as the importance of plastic creep gradually increases.
Place, publisher, year, edition, pages
2002. Vol. 65, no 13
high-temperature superconductors, high-tc superconductors, flux-creep, ac susceptibility, magnetic-relaxation, ii superconductors, quantum creep, crystals, dependence, vortices
IdentifiersURN: urn:nbn:se:kth:diva-21455DOI: 10.1103/PhysRevB.65.134525ISI: 000174903900146OAI: oai:DiVA.org:kth-21455DiVA: diva2:340153
QC 201005252010-08-102010-08-10Bibliographically approved