Dresden 2003 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 20: Postersitzung IV (Mesoskopische Systeme, Supraleitung: Massivmaterialien, Bandleiter, Pinning, Vortexdynamik, Transporteigenschaften, Korngrenzen)
TT 20.35: Poster
Donnerstag, 27. März 2003, 14:30–19:00, P2c, P2d
Guided vortex motion in Nb films on facetted substrate surfaces — •Oleksiy K. Soroka1, Michael Huth2, Valerij A. Shklovskij3, Jens Oster1, and Hermann Adrian1 — 1Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, D-55099 Mainz, Germany — 2Physikalisches Institut, Johann Wolfgang Goethe-Universität, Robert-Mayer-Str. 2-4, D-60054 Frankfurt/M., Germany — 3Kharkov State University, Physical Department, 4 Svobody Sq.,61077, Kharkov, Ukraine
Anisotropies of the viscous damping force of vortex motion in superconductors can cause a guiding effect on the vortices, i. e. there exists a preferred direction for the vortices to move. Guided vortex motion leads to the appearance of new components in the galvanomagnetic properties of the sample. One can observe an additional odd magnetoresistive component with respect to magnetic field reversal. Furthermore, an even contribution to the transverse (Hall) voltage emerges.
Guided motion of vortices in Nb films on facetted α−Al2O3 (1010) was observed by measuring the longitudinal and transversal resistivities of the sample. The thin film sample consisted of five microbridges oriented at the angles 0∘, 30∘, 45∘, 60∘ and 90∘ with respect to the facet ridges. Field inversion was used to separate the even and odd components of the measured magnetoresistivities to obtain the contributions caused by the guided vortex motion. We observed for the first time a sign reversal of the odd transverse component.