Low-field vortex dynamics in various high-T-c thin films
2002 (English)In: Pramana (Bangalore), ISSN 0304-4289, E-ISSN 0973-7111, Vol. 58, no 06-maj, 985-993 p.Article in journal (Refereed) Published
We present a novel ac susceptibility technique for the study of vortex creep in superconducting thin films. With this technique we study the dynamics of dilute vortices in c-axis oriented Y-123, Hg-1212, and TI-1212 thin films, as well as a-axis oriented Hg-1212 thin films. Results on the Hg-1212 and Tl-1212 thin films indicate that dislocation-mediated plastic flux creep of single vortices dominates at low temperatures and fields. As the temperature (or the field) is increased, the increasing vortex-vortex interactions promote a collective behavior, which can be characterized by elastic creep with a non-zero It exponent. Also, in some of these samples effects of thermally assisted quantum creep are visible up to 45 K in some of these samples. In Y-123 thin films, creep is found to be collective down to the lowest temperatures and fields investigated, while the quantum creep persists only up to 10-11 K.
Place, publisher, year, edition, pages
2002. Vol. 58, no 06-maj, 985-993 p.
vortex dynamics, flux creep, high temperature superconductor, thin film, ac susceptibility, flux-creep, ii superconductors, critical currents, single-crystal, magnetic-field, temperature, transition, lattice, hgba2cacu2o6+delta, susceptibility
IdentifiersURN: urn:nbn:se:kth:diva-24035ISI: 000176937700046OAI: oai:DiVA.org:kth-24035DiVA: diva2:342793
QC 201005252010-08-112010-08-11Bibliographically approved