Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1820253 | Physica C: Superconductivity and its Applications | 2008 | 4 Pages |
Abstract
This contribution reports on the magnetic response of a 200 nm thick Nb film, pierced with a set of 900 columnar indentations of nearly triangular cross section, forming a square lattice. The column effective diameter is 1 μm and the array lattice parameter is 10 μm. To probe the interaction of vortex matter with the array of antidots, we have excited the sample with an AC-field, so that flux trapped by the columns could be unpinned and admitted into the superconducting sea surrounding the defects. An order-disorder line was determined for this system, with a kink separating two regimes, suggesting a crossover from the efficient pinning regime, at lower temperatures, to a temperature-induced depinning. To exploit the influence of pinning efficiency on vortex dynamics, we have determined the order-disorder line at different angles between the applied field and the plane of the film. A plot of the field component perpendicular to the film versus temperature, gives a collapsed response near Tc, which splits for lower temperatures, as a consequence of pinning weakening due to the component of the applied AC-field perpendicular to the columns. Consistently, the kink tends to progressively disappear as the pinning strength decreases.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
J.S. Nunes, R. Zadorosny, A.A.M. Oliveira, C.M. Lepienski, E.J. Patiño, M.G. Blamire, W.A. Ortiz,