Effects of surface heavy ion implantation on Ag/BSCCO-2223 tapes

In this paper the effects of surface 0.25 GeV Au ion implantation on the superconductive properties of Ag/BSCCO-2223 tapes are studied. Columnar-defect length was ~5% of the whole sample thickness. Strong localisation phenomena and the occurrence of the localisation characteristic kink in the irreversibility line, IL, are observed at a point phase (Bkink, Tkink). Large shift of this line towards higher fields and temperatures and a very substantial enhancement of the critical current density, Jc, have been found. IL anisotropy and Jc anisotropy of the irradiated samples are switched off up to fields higher than Bkink. The characteristic trends, as well as their dose dependencies, are particular of such pinning strategy. The results give useful hints for further improvement of the Bi-2223 tape technology, concerning the introduction and influence of appropriate surface pinning.