ANGULAR-DEPENDENCE OF CRITICAL CURRENTS IN SILVER-SHEATHED TL-1223 TAPES

Experimental results on the angular dependence of the critical current densities in silver-sheathed Tl-1223 tapes are presented. We show, th at the improved texture of the Tl-based tapes leads to a better fit of the angular dependence of the critical current density J(c) to the 2D -model. Deviations are found at very low magnetic fields, where the cr ystallographic misalignment of the tape structure becomes dominant. We observe a rapid decay of J(c) with magnetic field, which implies weak -link dominated current transport. Both the angular and the magnetic f ield dependence of J(c) are measured on fluorine-free and fluorine-con taining samples.