Published online by Cambridge University Press: 28 February 2011
Au‐Sheathed Y‐Ba‐Cu‐O(YBCO) and Tl‐Ba/Sr‐Ca‐Cu‐O(TBSCCO) tapes were fabricated by the drawing‐rolling and subsequent unidirectional solidification. A typical microstructure of melt‐textured polycrystallite including fine particles of second phase(e.q. Y‐211) was observed. The Tl‐2223 tapes prepared at an optimized condition yielded Jc=15,300 A/cm2 at 77K in the absence of magnetic field, and l,100A/cm2 in a magnetic field of IT. The enhancement of Jc in a magnetic field is suggested to be due to the improvement of weak‐links in grain boundaries.