Pinning Energy and Irreversibility Line in GdSr2RuCu2O8

Transport properties of superconducting polycrystalline GdSr(2)RuCu(2)O(8) have been studied by resistivity versus temperature measurements in external magnetic fields up to 8 T. The analysis of the experimental data shows that an activated pinning mechanism is present with low values of the pinning energy and that an irreversibility line (IL) can be identified as the limit of dissipation due to a two-dimensional (2D) vortex motion. Comparing these results with those commonly observed in the case of other high temperature superconductors, a similarity with the 2D vortex motion for BSCCO is observed. This fact has been discussed considering the possible role played by the magnetic Ru ions on the superconducting properties of the compound. (C) 2004 Elsevier B.V. All rights reserved.