The distribution of transport current in YBCO coated conductor with zipper striations

摘要

An YBCO coated conductor with a zipper pattern striation is investigated by scanning laser microscopy (SLM). The distribution of transport current deduced from the VTSLM images shows that striations act as artificial barriers forcing the current to flow around them. Current sharing and redistribution are observed at the zipper area. We find the major dissipation mechanism in the sample in the superconducting state to be the current crowding at bottleneck areas. The bottleneck seems to be caused by the disabled filaments at and around the zipper area. Some filaments show the dissipation away from the zipper area. In general, we find that the lower J/sub c//sup */ areas have lower T/sub c//sup */ and high /spl delta/V/sub m/, which we consider as a sign of the current crowding. For the first time, we have demonstrated that there is a high temperature signature of the lower J/sub c//sup */ (high dissipation) area and VTSLM can detect the signature.