Experimental investigations on the critical vortex dynamics with controlled disorder

The possibility to enhance in a predictable way the superconducting properties behavior of a bulk material by introducing linearly correlated defects within a surface layer has been demonstrated. Ag/BSCCO-2223 tapes were irradiated by means of 0.25 GeV Au ions at different fluences, with a dose equivalent field Bφ ranging from 1 T to 5 T. The implantation depth was about 15 microm corresponding to about 15% of the total sample thickness. Sample independent enhancements of different a.c. and d.c. properties show up, due to vortex confinement in the whole sample. The sample independence exhibited by all the experimental findings as well as, on the other side, the dose dependence of the enhancements, allow to design in advance the performances of a monofilamentary tape where defect trenches of nanometric size are scratched