HIGH-FIELD BEHAVIOR OF ARTIFICIALLY ENGINEERED BOUNDARIES IN MELT-PROCESSED YBA2CU3O7-DELTA

Artificial bulk ''zero-angle'' boundaries parallel to the c axis have been engineered between large melt-processed YBa2CU3O7-delta (YBCO) gr ains and observed to carry a transport supercurrent at fields up to at least 5 T at 77 K. The temperature and angular dependencies of the bo undary resistance have exactly the same form as those of the grains, w hich is evidence that the grains are intimately coupled. The limiting mechanism for current transfer across these boundaries is, therefore, not a simple weak link or Josephson effect. This joining technique is extremely promising for production of macroscopic engineering artifact s. (C) 1998 American Institute of Physics.